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Discover Life 162 kinds match:
Agapanthinus callophila  [popup]
Agapostemon  [popup]
Ancylandrena  [popup]
Ancyloscelis  [popup]
Andrena  [popup]
Anthemurgus passiflorae  [popup]
Anthidiellum  [popup]
Anthidium  [popup]
Anthodioctes  [popup]
Anthophora  [popup]
Anthophorula  [popup]
Apis mellifera  [popup]
Ashmeadiella  [popup]
Atoposmia  [popup]
Augochlora  [popup]
Augochlorella  [popup]
Augochloropsis  [popup]
Aztecanthidium  [popup]
Bombus  [popup]
Brachymelecta  [popup]
Brachynomada  [popup]
Caenaugochlora  [popup]
Caenohalictus  [popup]
Calliopsis  [popup]
Caupolicana  [popup]
Cemolobus ipomoeae  [popup]
Centris  [popup]
Cephalotrigona  [popup]
Ceratina  [popup]
Chelostoma  [popup]
Chilicola  [popup]
Coelioxoides  [popup]
Coelioxys  [popup]
Colletes  [popup]
Conanthalictus  [popup]
Crawfordapis  [popup]
Ctenioschelus  [popup]
Dasypoda  [popup]
Deltoptila  [popup]
Diadasia  [popup]
Dianthidium  [popup]
Dieunomia  [popup]
Dinagapostemon  [popup]
Dioxys  [popup]
Dufourea  [popup]
Epanthidium  [popup]
Epeoloides  [popup]
Epeolus  [popup]
Epicharis  [popup]
Ericrocis  [popup]
Eucera  [popup]
Eufriesea  [popup]
Euglossa  [popup]
Eulaema  [popup]
Eulonchopria  [popup]
Exaerete  [popup]
Exomalopsis  [popup]
Florilegus  [popup]
Frieseomelitta  [popup]
Gaesischia  [popup]
Geotrigona  [popup]
Habralictus  [popup]
Habropoda  [popup]
Halictus  [popup]
Heriades  [popup]
Hesperapis  [popup]
Hexepeolus rhodogyne  [popup]
Holcopasites  [popup]
Hoplitis  [popup]
Hoplostelis  [popup]
Hylaeus  [popup]
Hypanthidioides  [popup]
Hypanthidium  [popup]
Lasioglossum  [popup]
Leiopodus  [popup]
Lestrimelitta  [popup]
Lithurgopsis  [popup]
Lithurgus  [popup]
Macropis  [popup]
Macrotera  [popup]
Martinapis  [popup]
Megachile  [popup]
Megalopta  [popup]
Megandrena  [popup]
Megommation  [popup]
Melecta  [popup]
Melipona  [popup]
Melissodes  [popup]
Melissoptila  [popup]
Melitoma  [popup]
Melitta  [popup]
Mesocheira  [popup]
Mesoplia  [popup]
Mesoxaea  [popup]
Mexalictus  [popup]
Micralictoides  [popup]
Microsphecodes  [popup]
Monoeca  [popup]
Mydrosoma  [popup]
Nannotrigona  [popup]
Neocorynura  [popup]
Neolarra  [popup]
Neopasites  [popup]
Nesosphecodes  [popup]
Nomada  [popup]
Nomia  [popup]
Odyneropsis  [popup]
Oreopasites  [popup]
Osiris  [popup]
Osmia  [popup]
Oxaea  [popup]
Oxytrigona  [popup]
Panurginus  [popup]
Panurgus  [popup]
Paragapostemon  [popup]
Paranomada  [popup]
Paranthidium  [popup]
Paratetrapedia  [popup]
Paratrigona  [popup]
Partamona  [popup]
Peponapis  [popup]
Perdita  [popup]
Pereirapis  [popup]
Plebeia  [popup]
Protandrena  [popup]
Protodufourea  [popup]
Protosmia rubifloris  [popup]
Protoxaea  [popup]
Pseudaugochlora  [popup]
Pseudoanthidium  [popup]
Pseudopanurgus  [popup]
Ptilocleptis  [popup]
Ptiloglossa  [popup]
Ptilothrix  [popup]
Rhopalolemma  [popup]
Scaptotrigona  [popup]
Scaura  [popup]
Simanthedon linsleyi  [popup]
Sphecodes  [popup]
Sphecodosoma  [popup]
Stelis  [popup]
Svastra  [popup]
Syntrichalonia  [popup]
Temnosoma  [popup]
Tetragona  [popup]
Tetragonisca  [popup]
Tetraloniella  [popup]
Tetrapedia  [popup]
Thygater  [popup]
Townsendiella  [popup]
Trachusa  [popup]
Triepeolus  [popup]
Trigona  [popup]
Trigonisca  [popup]
Triopasites  [popup]
Xenoglossa  [popup]
Xeralictus  [popup]
Xeroheriades micheneri  [popup]
Xeromelecta  [popup]
Xylocopa  [popup]
Zacosmia maculata  [popup]
Zikanapis  [popup]


REMAINING (number with state)
Agapanthinus vs Gaesischia
 Agapanthinus MALE terminal flagellomere modified with a distinct KNOB or HOOK at the tip that appears to be directed laterally T2-3 with a dense basal band of WHITE, plumose hairs, and a similarly dense band of BLACK, simple hairs stretching from the basal band to the apical rim or nearly so, WITHOUT additional white hairs at the rim except at the very lateral edges where the basal band may widen and bend to touch the rim - FEMALE mid tibial spur SHORT, equal to less than half the length of the tibia - This monotypic genus is rare, reported only from the desert areas of Baja California and California - Size ranging from 9-11mm according to Bees of the World (1)
 MALE terminal flagellomere rounded at the tip Tergal hair color and form is variable, sometimes similar to Agapanthinus and sometimes not FEMALE mid tibial spur LONG, equal to or greater than half the length of the tibia - This genus is widespread from the southwest US into South America (1)
Agapanthinus vs Tetraloniella
 Agapanthinus - Terminal flagellomere of MALE modified, HOOK-LIKE - FEMALE mid tibial spur short, equal to less than half the length of the tibia itself - T2-3 of FEMALE with a dense basal band of white hairs and a similarly dense band of black hairs posterior to this, this black bands coverage nearly reaching the rim - The single species of this genus is rare, restricted to the desert areas of Baja California and California - Size ranging from 9-11mm according to Bees of the World (1)
 Tetraloniella MALE terminal flagellomere unmodified - FEMALE mid tibial spur LONG, equal to more than half the length of the tibia itself T2-3 hair patterning variable, often with a light basal band of hair but usually also with a similar dense apical band of light hair, although some species appear to share a similar pattern to that of Agapanthinus - The moderately uncommon species of Tetraloniella are found throughout the western and central US, extending southward well into Central America - Size variable, ranging from 9-15mm according to Bees of the World (1)
Agapostomen vs selected other genera
 Other selected genera - Rear face of propodeum not surrounded by a clearly defined raised line, but instead rounding over and integrating smoothly into the lateral faces of the propodeum, does not have distinct transverse striations (16)
 Agapostemon - Rear face of propodeum CIRCLED or bordered by a clearly defined raised line or carina, creating the appearance of a shield which has transverse striations throughout (1)
Ancyloscelis vs Other selected genera
 Others - Hind wing, second abscissa of M Cu usually not over twice and rarely about three times as long as cu-v - MALE antenna usually greatly elongated - Hind leg not greatly enlarged - FEMALE hind basitarsus with a broad dense brush extending beyond the base of the second tarsal segment (12)
 Ancyloscelis - Hind wing, second abscissa of M Cu three times as long as cu-v - MALE and FEMALE antennae similar in length - MALE hind leg greatly enlarged - FEMALE hind basitarsus without apical brush - Uncommon, AZ, TX, CO (1)
Andrena vs selected Halictinae
 Others - Basal vein strongly HUMPED or CURVED towards its base, at times almost sharply - FEMALE with facial foveae absent (9)
 Andrena - Basal vein STRAIGHT, feebly curved or curved smoothly throughout its length - FEMALE with distinct shallow concave areas, or foveae, located between the upper part of the compound eyes, antennal bases and ocelli, which are filled with extremely short, dense, microscopic light or dark hairs (3)
Andrena vs selected other genera
 Others - Facial foveae absent - Scopa principally on hind leg tibia - One subantennal suture under each antenna (5)
 Andrena - Female with distinct shallow concave areas or foveae between the upper part of the compound eyes and the antennal bases and the ocelli, these foveae covered with dense, very short, microscopic hairs - Scopa well developed on rear leg femur and trochanter - Two sub-antennal sutures present (3)
Andreninae vs Panurginae
 Panurginae Forewing, marginal cell truncated such that the tip is not on or near the upper margin of the wing, or if not bluntly truncated then with the tip of the marginal cell clearly pointed away from the margin - FEMALE facial foveae, when present, HAIRLESS and usually shiny (8)
 Andreninae Forewing, marginal cell either pointed or slightly rounded, the tip on or near the upper margin of the wing - FEMALE facial foveae, when present, HAIRY, lined with microscopically minute hairs and usually dulled as a result (3)
Anthemurgus vs Pseudopanurgus
 Anthemurgus Propodeal triangle finely reticulate and covered with short hairs - MALE clypeus with one small central yellow spot (1)
 Pseudopanurgus Propodeal triangle with raised lines, thus being striate or finely areolate, without any short hairs, and in some small species densely pitted - MALE clypeus completely or almost completely yellow (1)
Anthemurgus vs other selected genera
 Other genera - Episternal groove ABSENT - T2-5, apical impressed area of rim lacks hair - MALE bees of these genera are often black with yellow markings on the head and legs (2)
 Anthemurgus - Episternal groove PRESENT, remaining independent of the scrobal groove and extending ventrally past the intersection of the two - T2-5, apical impressed area of rim usually distinctly hairy - The single species of this genus is entirely black (1)
Anthidiellum vs selected other genera
 Others - Scutellum rounded over, or rarely bilobed, usually not overhanging metanotum and propodeum, if it is overhanging then it is not thin and shelf-like - Subantennal sutures not conspicuously arched (10)
 Anthidiellum - Scutellum extended posteriorly as broad, THIN, SQUARED-OFF SHELF, over-hanging the metanotum and propodeum - Subantennal sutures distinctly ARCHED OUTWARD (1)
Anthidium vs Dianthidium
 Anthidium - Thorax, pronotal lobe, entirely opaque - Thorax, propodeum without a shallow hollow or foveae behind the spiracle - Thorax, mesepisternum usually lacking or with only weak ridges separating anterior and lateral surfaces - FEMALE, Head, mandible with five or more close set teeth (1)
 Dianthidium - Thorax, pronotal lobe, broadened and with a wide TRANSPARENT rim - Thorax, propodeum with a large foveae behind the spiracle - Thorax, mesepisternum with a clear ridge or carina separating the anterior surface nearest the head from the larger lateral surface which faces outward from the side below the wing - FEMALE, Head, mandible with four or fewer well-separated teeth (1)
Anthidium vs Pseudoanthidium
 Anthidium - T2-3, pits on the depressed rim smaller, more closely spaced, and of greater density in comparison to pits on the remainder of the segment - Subantennal sutures straight or nearly so - A locally regularly occurring genus, particularly the two introduced species - In comparison, larger, size ranging from 17 mm to barely 8mm (1)
 Pseudoanthidium T2-3, pits on the rim no different, or only slightly more closely spaced and smaller in comparison to pits on the remainder of the segment, rim area often with no discernible depression - Subantennal sutures clearly arch outward - Rare, recently discovered European species found in urban and disturbed areas of Baltimore and New York City, but expected to spread (1)
Anthophora vs Deltoptila
 Anthophora - Malar space usually SHORT, well under a third the width of the mandible base - Forewing, first recurrent vein meeting the bottom of the second submarginal cell at about the MIDDLE (1)
 Deltoptila - Malar space LONG, usually nearing or about half the width of the mandible base - Forewing, first recurrent vein meeting the bottom of the second submarginal cell at or near its APEX towards the tip of the wing, often joining at the intersection with the bottom of the second transcubital vein (1)
Anthophora vs Habropoda
 Anthophora - Forewing, length of the marginal cell SHORTER than the distance from the tip of the marginal cell to the tip of the wing - Submarginal cells lining MORE THAN half the length of the marginal cell, with third transcubital vein ending beyond middle of the marginal cell - Upper and lower margins of third submarginal cell about EQUAL in length - First recurrent vein ending near MIDDLE of the bottom of the second submarginal cell (1)
 Habropoda - Forewing, length of the marginal cell ABOUT AS LONG as distance from the tip of the marginal cell to the tip of the wing - Submarginal cells line only ABOUT HALF the length of the marginal cell, with third transcubital vein ending near middle of the marginal cell - Upper margin of third submarginal cell SHORTER than the lower margin - First recurrent vein ending NEAR THE APEX of the second submarginal cell (1)
Anthophorini vs Melectini
 Melectini - Cleptoparasitic bees - Forewing, marginal cell broadly rounded apically, the tip usually located along the mid-line of the marginal cell and thus quite a distance away from the edge or margin of the wing, the tip usually only slightly extending past the last submarginal cell, if at all - Hindwing, second abscissa of M Cu shorter than cu-v - FEMALE S6 surpassing T6 and visible from above, taking the form of a sheath which at least partially envelops the sting - The thorax and abdomen is often patterned by very dense, light-colored appressed hairs throughout - Labrum nearly always longer than broad, although sometimes may appear about as broad as long (4)
 Anthophorini Forewing, marginal cell tip narrowly rounded or pointed, the tip located within a few vein widths of the edge or margin of the wing - Hindwing, vein cu-v shorter than the second abscissa of M Cu or sometimes about equal - FEMALE S6 variable, but virtually never extending past T6 such that it is visible from above, appearing relatively flat and NOT tubular around the sting Labrum usually broader than long, only uncommonly as long as broad (3)
Anthophorula and Exomalopsis vs Monoeca and Paratetrapedia
 Anthophorula and Exomalopsis - Mandible SIMPLE, lacking a subapical tooth - Integumental white or yellow markings are generally lacking, although sometimes may be present on the head Hind basitarsus NARROWER, sometimes one-fourth as wide as long but usually thinner, be careful as there are many dense hairs that can make the basitarsus seem broader - Tergites MOST OFTEN have distinct, light colored hair bands along the rim in relation to the dark integumental color- FEMALE scopal hairs usually plumose to the very apex of each hair or nearly so (2)
 Monoeca and Paratetrapedia - Mandible, SUBAPICAL TOOTH near the tip, sometimes two - Integumental white or yellow markings are more common in this group, often present on the head and sometimes on male abdomens as well - Hind basitarsus WIDER, this state is variable but usually width is at least one-third length or wider - Tergites may have significant hair present, but the color of the hair usually blends well with the color of the integument - FEMALE scopal hairs long and simple, surpassing the interspersed, plumose hairs (2)
Anthophorula vs Exomalopsis
 Anthophorula - MALE clypeus marked with YELLOW OR WHITE - FEMALE basitibial plate SMALLER in direct comparison, appearing flat without a raised margin and with less hair centrally, if this is not the case and there is no central bare area then there is no transverse carina on T1 near its base (2)
 Exomalopsis - MALE clypeus BLACK - FEMALE basitibial plate LARGER in direct comparison, often appearing to have a raised ridge running around its perimeter that encircles an area of denser hair (1)
Apis vs MALE Eulonchopria vs Meliponini vs All others
 Others - Rear leg tibial spurs PRESENT (143)
 Meliponini - Absent - Eyes WITHOUT hairs - Marginal cell incomplete or weakened (16)
 Apis - Absent - Eyes hairy - Marginal cell complete (1)
Ashmeadiella vs selected other genera
 Others - Mesepisternum, the narrow front or anterior surface of this thoracic plate adjacent to the pronotum, with no sharp boundary or sharp change in sculpturing - MALE T6 without four teeth along the rim (7)
 Ashmeadiella - Mesepisternum, the narrow front or anterior surface of this thoracic plate adjacent to the pronotum, smooth and shining, CLEARLY separated from pitted rear surface by noticeable raised line or carina - MALE T6 with four teeth along its rim (1)
Atoposmia vs Hoplitis
 Atoposmia - Anterior surface of T1 a broad concave or flat area margined above by a sharp line usually as long as one half the width of T1 although much less in some cases, thus the profile of T1 angulate at the summit of the anterior surface - S6 of male without basal flaps - Parapsidal lines usually much less than half as long as tegulae - S2 of male nearly always much larger than S3 which is broadly emarginate and fringed medially which is hidden medially by S2 Body robust - Western only - Formerly Anthocopa (1)
 Hoplitis - T1 with anterior surface not broadly concave or flat and not margined by a sharp line except sometimes medially thus profile of T1 not angulate - S6 of male with basal hairless translucent flaps - Parapsidal line often over half as long as tegula - S2 of male usually not enlarged and not hiding the middle of the S3 margin although the fully exposed S2 is sometimes emarginate and fringed - Body rather elongate - Fairly common, occurring in east and west (1)
Atoposmia vs Protosmia
 Atoposmia - Female clypeus variable, but not with a spatulate projection extending apicomedially from the rim - At the middle of the base of the dorsal face of the propodeal enclosure, this being the area which borders the metanotum, the rear edge of this dorsal face is rounded over into the vertical face of the propodeum, although sometimes there may be a carina laterally, and there is often a small depression also found medially - T6 of male relatively evenly convex throughout, not noticeably more convex apicomedially, often with T7 visible beneath (1)
 Protosmia - Female clypeus with a distinct apicomedial SPATULATE PROJECTION - The meeting of the dorsal and vertical faces of the propodeal enclosure are separated by a raised line or CARINA which may be somewhat weakened medially, with the dorsal face taking the form of a thin latitudinal strip in which longitudinal striations are present throughout - T6 of male strongly convex apicomedially, such that T7 below is normally not visible (1)
Augochlora and Augochlorella vs Neocorynura
 Augochlora and Augochlorella - In the Female, the inner corner of the clypeal suture that defines the boundary between the paraocular area and the lateral sides of the clypeus forms either a right angle or an acute angle, although in some few Augochlorellla it may appear weakly obtuse - Female rear leg with the inner tibial spur having teeth about equal in size to those of the outer tibial spur - Males with T1-2 relatively normal, broader than long or sometimes about equal (2)
 Neocorynura - In the Female, the inner corner of the clypeal suture that defines the boundary between the paraocular area and the lateral sides of the clypeus forms either a distinctly obtuse angle - Female inner hind tibial spur with very large, irregularly-spaced teeth, the longest of which are several times longer than wide, these teeth MUCH larger than the relatively normal teeth of the outer hind tibial spur - The male abdomen is constricted on T1-2 such that the two together often appear funnel-shaped with the basal edge of T1 narrow and the apical edge of T2 wide and T1 clearly much longer than it is broad (1)
Augochlora vs Pereirapis
 Augochlora - Clypeus nearly entirely metallic green or blue down to the rim, but in some males there is a small yellow strip on the rim - In females, the sutures defining the paraocular lobes along the boundary with the clypeus are clearly acute - The marginal cell of the forewing is apically truncate, often only minutely so - In direct comparison, usually larger (1)
 Pereirapis - Clypeus with a distinct non-metallic apical area which may equal up to half of the length of the clypeus, this space being yellow in males and dark in females - In females, the paraocular lobes extend down onto the clypeus from the sides with their tips appearing obtuse or right-angled - The marginal cell of the forewing appears pointed on or very near the edge of the wing - In direct comparison, usually smaller (1)
Augochlorella vs Pereirapis
 Augochlorella - In FEMALES, the surface texture on the posterior edge of the propodeal triangle is smooth or marked with fine lines - The inner hind tibial spur of FEMALES is abruptly and STRONGLY THICKENED near the base, the point at which this happens being clearly the thickest along the length of the spur - S4 of male either straight medially or only weakly concave, the hairs present at the sides, if any, being of normal length in comparison to the other hairs nearby - The integument of the terga is most often strongly metallic green, although in some species there may be some brownish coloration also present - In direct comparison, usually larger than 5mm (1)
 Pereirapis - In FEMALES , the surface texture on the posterior edge of the propodeal triangle is VERY GRAINY, resembling sandpaper - The inner hind tibial spur of the female is only slightly thicker at the base than elsewhere, if at all, this due to a gradual thickening as you travel from the tip to the base - S4 of male concave or emarginate along the rim, with unusually LONG HAIRS arising from the sides of this emargination - The integument of the terga usually has weaker metallic green reflections than in Augochlorella, these reflections often only visible when viewed from certain angles with the integument appearing BROWNISH otherwise - In direct comparison, usually smaller, around 5mm (1)
Augochlorini vs other Halictid genera - Female, abdomen, T5, presence of a longitudinal medial slit originating on the rim
 Other genera - Distinct slit ABSENT, but sometimes very slightly emarginate nonetheless (20)
 Augochlorini - Present and the slit equal to at least a third of the longitudinal length of the segment - Note that the slit can often be obscured by hairs, although a pin may be used to move these hairs aside for a better view if necessary (10)
Augochloropsis vs other bright green Halictids
 Others - Tegula OVAL, inner margin gently rounded out as in most other species - Basitibial plate of female extending well beyond apex of femur, except in the Central and South American genus Megommation - Rims of T1 and T2 with scattered hairs the same size as those on the rest of segment, not having a series of longer bristles or hairs (12)
 Augochloropsis - Tegula D-SHAPED and is flat or slightly bent inward along the inner margin - Basitibial plate of female VERY SHORT, scarcely extending past apex of femur - First and second top abdomen segments - T1 and T2 - usually with a series of simple bristles lining the rim and creating a thin to thick band of hair (1)
Aztecanthidium vs Dianthidium
 Aztecanthidium - The anterior margin of the scutum, near the head, is normal, forming a gentle curve to the boundary with the pronotum - The posterior edge of the scutellum appears BILOBED, with these lobes being the only parts of the rim of the scutellum which clearly extend posteriorly past the metanotum - The scutellar rim is interrupted in its continuity by a pair of lobes which extend posteriorly much farther than the rest of the rim - Propodeal spiracle without a fovea present posterior to it, the area usually densely pitted (1)
 Dianthidium - The anterior margin of the scutum is strongly declivous, the margin appearing to project forward over the pronotum at a slightly acute angle creating both a VERTICAL, anterior face and the horizontal, posterior face - The posterior rim of the scutellum usually extends posteriorly farther than the metanotum, such that it hangs over it, for the majority of its apparent latitudinal width - The scutellar rim is either entire or with a slight medial indent - Propodeal spiracle usually, but not always, with a fovea present posteriorly, the sculpturing and pitting of the surface clearly interrupted by a depression, when present (1)
Bombus vs Eulaema and Euglossa and Eufriesea
 Eulaema and Euglossa - Proboscis or tongue in repose reaching beyond base of abdomen - Male with a deep hairy groove on the posterior surface of the hind tibia - A comb of bristles replaces the jugal lobe on the hind wing - Uncommon in US, mainly FL, TX, AZ, and possibly NM (4)
 Bombus - Proboscis or tongue in repose not reaching the base of the abdomen - Posterior tibia of male not deeply grooved - No comb of bristles on the base of the hind wing Common and widespread (1)
Brachymelecta vs other selected genera
 Not as above, with the marginal cell extending beyond the submarginal cells significantly and other characters variable (9)
 Brachymelecta - This is an extremely rare genus known from one male specimen collected in Nevada, which resembles typical Melectini except for the presence of dense, appressed hairs covering the tergites and having only two submarginal cells - Marginal cell not or scarcely extending beyond submarginal cells - The known specimen is 9mm in length (1)
Brachynomada vs Nomada
 Brachynomada - Malar space with top and bottom parallel - Vertex and mesoscutum largely without pits - Middle coxa as long as distance from its summit to the hind wing base (1)
 Nomada - Malar space longer on anterior end, side closest to clypeus, and shorter on posterior side, not parallel thus malar space looks more like an angle - Vertex and mesoscutum usually with pits - Middle coxa shorter than distance from its summit to hind wing base (1)
Brachynomada vs Triopasites
 Brachynomada - Forewing with either TWO OR THREE submarginal cells - The center of the rim of S1 is only weakly triangular such that , if at all, and the rim lies relatively flat against the base of S2 without being reflexed and pointing ventrally - Males of the subgenus Melanomada have a small spike present near the base of the hind femur, on the lower side - In direct comparison, usually DARKER BLACKISH bees, although some are also variably reddened (1)
 Triopasites - Forewing with THREE submarginal cells - At the center of the rim of S1, the somewhat medially flattened, but generally triangular projection is reflexed such that, at the rim, it appears to be pointing ventrally - Males do not have a small spike near the base of the hind femur - In direct comparison, more REDDISH than many Brachynomada species, with red being the primary integumental color in nearly all specimens observed (1)
Caenohalictus vs Dinagapostemon and Paragapostemon
 Dinagapostemon and Paragapostemon Propodeum, dorsal surface clearly LESS THAN twice the longitudinal length of the metanotum when compared medially FEMALE hindleg, inner tibial spur with 5-11 TEETH - In direct comparison, these species are usually LARGER (2)
 Caenohalictus Propodeum, the dorsal surface just posterior to the metanotum, about TWICE the longitudinal length of the metanotum when compared medially, - FEMALE hindleg, inner tibial spur with 3-4 TEETH- In direct comparison, these species are usually SMALLER (1)
Calliopsis vs selected other genera
 Others Face, inner subantennal suture usually much longer than diameter of antennal socket - Anterior tentorial pit found at JUNCTION between outer subantennal suture and epistomal suture or just below the junction - Outer subantennal suture sometimes absent in some Heterosarus and Pseudopanurgus species FEMALE S5 rim straight or concave MALE S4 and S5 rims without projections (8)
 Calliopsis Face, inner subantennal suture little if any longer than diameter of antennal socket - Anterior tentorial pit found at lower end of outer subantennal suture, usually NOT at junction with epistomal suture FEMALE S5 rim convex MALE S5 rim usually with a well-developed median rearward projection MALE S4 rim also with projection or at least the rim is strongly convex (1)
Caupolicana and Ptiloglossa vs selected other genera
 Others - Not as in Caupolicana or Ptiloglossa (64)
 Caupolicana or Ptiloglossa Forewing, first recurrent vein meeting or coming within 1-2 vein widths of FIRST transverse cubital vein (3)
Caupolicanini vs other selected genera
 Caupolicanini Antennae, F1 elongated, petoliate and unusually slender, subequal to or greater than the length of the scape Mesepisternum, episternal groove COMPLETE, continuing past the scrobal groove (4)
 Other selected genera Antennae, F1 short and only slightly petoliate, if at all, clearly LESS THAN the length of the scape Mesepisternum, episternal groove INCOMPLETE, absent below the scrobal groove (1)
Centris vs Epicharis
 Centris Head, vertex usually WITHOUT abnormally thick, cord-like hairs, or, if present, always short and just barely reaching the scutum Forewing, length of the marginal cell SHORTER than the distance from the apex of the marginal cell to the wing tip (1)
 Epicharis Head, vertex WITH long, whip-like hairs present among normal hairs, usually arising laterally from the area behind the compound eyes, these hairs stretch back over the scutum often all the way to the tegulae, although in some species they may be shorter such that they just slightly reach past the scutum, be careful as many specimens may have had these hairs rubbed off Forewing, length of the marginal cell LONGER than the distance from the end of the marginal cell to the wing tip (1)
Cephalotrigona vs selected other genera
 Other genera Head, lower and upper areas of the face are about equal in terms of surface luster and pitting Vertex, NOT carinate along the back of the head Mandible, dentation variable, usually not as in Cephalotrigona (7)
 Cephalotrigona Head, lower areas of face and gena shining and coarsely punctate, upper area of face dull and minutely punctate Vertex, well-defined PREOCCIPITAL CARINA present along the rear of the head, this ridge usually shiny Mandible, single tooth located close the base of the mandible (1)
Ceratina vs selected other genera
 Other genera - Body not shiny, or else with areas covered by hairs or hair bands Tergites, hairs dense and may obscure the surface in some areas, often forming pale abdominal latitudinal hair bands - Body usually robust - Pygidial plate usually present (41)
 Ceratina Body, shiny, metallic dark blue or dark green or rarely jet black, and slender, no areas covered by dense hairs Tergites, abdominal hairs short and sparse NOT forming distinct latitudinal bands of pale hairs FEMALE clypeus usually with short longitudinal median white or yellow bar FEMALE pygidial plate absent but apical end of abdomen coming to a sharp, small, point - MALE abdomen ends with a projecting small shelf-like thin flange or plate (1)
Chelostoma vs Hoplitis
 Hoplitis - Body less slender, but still slender compared to other bee species, with the shortest distance between tegulae GREATER than length of scutum (2)
 Chelostoma - Body very slender, shortest distance between tegulae LESS than or EQUAL TO length of scutum (1)
Click here to choose the groups of genera to include in the guide
 ADMIN ONLY - ALL (161)
 Mexico - Caution, this area is under development, some genera still need to be added and some unresolved groups may occur - Please report any discrepancies, as limited specimens were available for some groups - Click here for ALL genera found in Mexico (146)
 United States and Canada - Click here for ALL genera found in the entire US and Canada (111)
 Eastern United States and Canada ONLY - Click here for the genera found East of the Mississippi (67)
 Caribbean islands, not including Trinidad/Tobago - Under development, use with caution - Click here for ALL genera found in the Caribbean (39)
 Ireland and Great Britain - Under development but usable with caution (28)
Coelioxoides vs all other genera
 Other genera - Combination not as above (18)
 Coelioxoides - Body form slender and largely hairless, with scopa absent and abdomen characteristically tapering much like in Coelioxys - Labrum about as broad as long or only slightly longer than broad - S6 of female extending back farther than T6, visible from above at least slightly as a result - Male lacking hind tibial spurs (1)
Coelioxys vs selected other genera
 Coelioxys - Pygidial plate absent - Labrum longer than broad - Mandible with at least one tooth below the tip (2)
 Others - Pygidial plate present in both sexes, although often hidden by T5 in females - Labrum broader than long - Mandible simple, with no additional teeth (1)
Colletes vs all other genera
 Others Forewing, second recurrent vein usually straight or only slightly arched (100)
 Colletes Forewing, second recurrent vein, lower portion distinctly arched outward toward wing tip making the shape of the vein appear s-shaped (1)
Conanthalictus vs Halictus
 Conanthalictus Propodeum, dorsal face, which is directly posterior to the metanotum, clearly longitudinally longer than the scutellum when compared medially - MALE mandible, multi-dentate or truncated process found about halfway down the upper edge MALE clypeus WITHOUT a yellow border on the apical rim - In direct comparison, apical pale hair bands on the terga are much sparser and usually interrupted medially (1)
 Halictus Propodeum, dorsal surface subequal or shorter in longitudinal length to the scutellum when compared medially Mandible, either a simple blade or with an inferior rounded tooth set slightly back from the tip, often making the end of the mandible look mitten-like MALE clypeus usually with a yellow border on the apical rim - In direct comparison, pale apical hair bands on the terga are much denser and only rarely interrupted medially (1)
Conanthalictus vs Sphecodes
 Conanthalictus Clypeus, very SHORT, the length along the rim equal to more than twice the maximum longitudinal clypeal length - Pronotal lobe and collar, rounded and not divided between the anterior and posterior areas by a strong ridge Body, very finely tessellate throughout, giving its integument the appearance of extremely fine sandpaper, and without the kind of coarse sculpturing that can be seen on the propodeum of Sphecodes - MALE mandible often with a distinctly MULTI-FACETED SUBAPICAL TOOTH along the upper margin of the mandible which appears to have several small teeth arising from it, usually located about one third of the length of the mandible from its tip (1)
 Sphecodes Clypeus, LONGER, the length along the rim usually less than twice as wide the maximum longitudinal clypeal length - Pronotal lobe and collar, strongly CARINATE, the dorsal area of the collar divided from the lower area of the pronotum by a well-defined ridge Body, overall much more COARSELY SCULPTURED, this being especially true on the propodeum where it is almost always AREOLATE, divided into raised reticulate cells - MALE mandible WITHOUT a multi-faceted tooth set behind the tip of the mandible that appears to have multiple teeth on it, although some species have a simple subapical tooth which appears to be anything from a slight angling of the upper edge of the mandible edge to a rounded tooth similar to other halictids (1)
Conanthalictus vs. Sphecodosoma
 Conanthalictus - Body minutely roughened and basically dull - Apical margin of clypeus more than 2 times length of clypeus More common in direct comparison (1)
 Sphecodosoma - Body largely shiny although pitted, not minutely roughened - Apical margin of clypeus less than or equal to two times the length of the clypeus More rare in direct comparison (1)
Crawfordapis vs Caupolicana and Zikanapis - The form of the base of the marginal cell
 Caupolicana and Zikanapis - The marginal cell is only weakly narrowed near the base and only very slightly intruding along the upper margin of the second submarginal cell if at all (2)
 Crawfordapis - The marginal cell is GREATLY narrowed at the base, this due to its intrusion into about one fourth the length of the first submarginal cell along its upper margin (1)
Dasypoda vs Macropis
 Dasypoda Forewing, two or three submarginal cells, if two then the second submarginal cell is about as long as the first when measuring by their greatest lengths FIRST TRANSCUBITAL VEIN, which divides the first and second submarginal cell, is roughly PERPENDICULAR to the veins above and below, the FIRST RECURRENT VEIN usually located within THREE vein widths of the base of the first transcubital vein - FEMALE hindleg, basitarsi SLENDER AND ELONGATE, more than twice as long as wide, most often closer to four times longer than wide - In general, these bees are LARGER than Macropis - This genus is only found in the old world (1)
 Macropis Forewing, with only two submarginal cells, the second of which is shorter than the first when measuring by their greatest lengths FIRST TRANSCUBITAL VEIN, which divides the first and second submarginal cell, is SLANTED such that its lower end is at least FIVE vein widths from the upper end of the first recurrent vein - Female hindleg, basitarsi SHORT AND STOUT, most often close to only twice as long as they are wide, and never four times as long as wide - In general, these bees are SMALLER than Dasypoda - This genus is found in both the Old World and North America (1)
Deltoptila vs Habropoda
 Deltoptila Head, malar space LONG, usually equal to half or more of the basal width of the mandible, face appearing long and horse-like as a result - Hind wing, first abscissa of vein cu-v usually meeting M Cu at nearly a RIGHT angle or at least about 50 degrees, appearing close to transverse across the width of the wing itself - Tongue, glossa with a small but distinctly separate structure, the flabellum, present at the very tip which can be either fan-like or pointed (1)
 Habropoda - Malar space SHORT, equal to much LESS THAN half the basal width of the mandible - Hind wing, first abscissa of vein cu-v usually meeting M Cu at an ACUTE angle, about 45 degrees or less - Flabellum absent, glossa without a small, separate structure at the very tip (1)
Dianthidium vs Trachusa
 Dianthidium Thorax, pronotal lobe, broadened and outer edge or rim is TRANSPARENT - Thorax, scutum, front margin where it abuts the pronotal collar angles abruptly downward, steeply sloping or vertical like a cliff Thorax, metanotum, rear margin with short, white felt-like, prone, short highly plumose hairs (1)
 Trachusa Thorax, pronotal lobe, entirely OPAQUE - Thorax, scutum, front margin forms a continuous, gentle curve of less than 45 degrees downward to the margin of the pronotum - Thorax, metanotum, rear margin no felt-like hairs present (1)
Dieunomia vs Melitoma
 Dieunomia - Abdomen dark - Tongue short never extending further than the front part of the thorax (1)
 Melitoma - Abdomen prominently lined with bands of white hairs - Tongue very long, extending to the abdomen even when in a folded position (1)
Dieunomia vs Nomia
 Dieunomia Abdomen, tergite rims with dense hair, rims not strongly colored, normally dark brown or black (1)
 Nomia Abdomen, tergite rims bare, smooth and hairless, forming green, blue, or yellow-green enamel-like or mother-of-pearl borders, very distinctive (1)
Dieunomia vs Selected Other Genera - Note that Dieunomia is a halictid but its very large size and general Eucerine body shape can lead to errors for those who look too quickly
 Other selected genera Scutum, tegula ovoid or flattened on the anterior outside edge Forewing, marginal cell with apex TRUNCATE or BENT AWAY from margin, first and third submarginal cells not subequal posteriorly Hindwing, jugal lobe usually much less than three-fourths as long as vannal lobe - MALE rear tibia normal (23)
 Dieunomia Scutum, tegula elongate with a distinct posterior angle, giving it a kidneybean-like appearance Forewing, marginal cell with apex ROUNDED on or almost ON WING MARGIN, first and third submarginal cells subequal posteriorly, usually not much longer than the second submarginal cell, which is quadrate - Hindwing, jugal lobe about three-fourths as long as vannal lobe - MALE rear tibia with distinct and obvious and large flattened flange projecting from the side (1)
Dinagapostemon vs Paragapostemon
 Dinagapostemon Abdomen, tergites are relatively evenly curved laterally, without longitudinal carinae - In direct comparison, the metallic green or blue reflections are much more limited, often with few or no metallic green or blue reflections in the apical half of the tergites - MALE antennae with apical segments HIGHLY MODIFIED, crenulated, resembling dulled saw blades ventrally and with indents present dorsally (1)
 Paragapostemon Abdomen, tergites with distinct longitudinal CARINAE or raised lines found laterally where the integument begins to turn ventrally - In direct comparison, the metallic green or blue reflections of the tergites are much more extensive and usually cover most or all of each tergite - MALE antennae similar to other Halictine groups (1)
Dufourea vs. Micralictoides and Sphecodosoma
 Micralictoides and Sphecodosoma Forewing, distance from apex of stigma to apex of marginal cell LESS THAN or EQUAL TO distance from apex of marginal cell to wing tip MALE S8 without basal lobes, but rather with a blunt median projection called a SPICULUM - Occurs only in Southwest (2)
 Dufourea Forewing, distance from apex of stigma to apex of marginal cell at least AS GREAT AS distance from apex of marginal cell to the wing tip MALE S8 with a pair of basal lobes - Occurs in East and West, only genus with antenna low on face in East (1)
Epeoloides and Osiris vs other selected genera
 Other genera - Combination not as above (28)
 Epeoloides and Osiris - Cleptoparasitic bees - Forecoxae vaguely triangular, with a ventral carina present along the inner margin near the base of the coxae - Forewing with three submarginal cells - Stigma of forewing long, 3-8x the length of prestigma - S6 of female very elongate in Osiris, forming a shaft which normally envelops the sting, although in Epeoloides this is less developed and usually at least part of the sting is visible beyond the tip of the elongate S6 - Pseudopygidial area of T5 not present in females - Stipital comb, a brush of hairs present within a concavity found near the tip of the stipes, absent - Usually resembling Nomada in general body form (2)
Epeoloides vs Epeolus or Triepeolus
 Epeolus or Triepeolus - Axilla tip clearly and distinctly projecting from the sides of the scutellum, forming a spine or a sharp angle, very obvious - A regular but uncommon group of species (2)
 Epeoloides - Tip of axilla not projecting from the thorax body, but instead the axilla smoothly follows the rim of scutellum and is undistinguished in shape or form - An EXTREMELY rare bee, fewer than 5 recent records (1)
Epeoloides vs Osiris
 Epeoloides - The tip of the marginal cell is rounded, its farthest apex clearly separate from the edge of the wing by many vein widths as a result - The distance between the male compound eyes is much greater at the bottom of the eyes than at the top - The shaft which envelops the female sting is shorter and does not usually cover the entire sting, usually the sting is extending well beyond its end - Integument of body black, sometimes with brown on the legs or abdomen (1)
 Osiris - The marginal cell is pointed and usually right by the edge of the wing, if separate then only by 1-2 vein widths - The distance between the male compound eyes is either greater at the top of the eyes or about equal to the bottom - The shaft which envelops the female sting is longer and the female sting is quite often entirely covered as a result - Integument of body variable, usually with extensive reds or yellows but some small number of species are primarily black (1)
Epeoloides vs selected Melectini
 Other genera - Marginal cell much shorter than distance from its apex to wing tip - Body with patches of small, appressed, pale, short hairs - Wings with large bare areas and coarsely papillate at wing tips (2)
 Epeoloides - Marginal cell longer than distance from its apex to wing tip - Body without areas of small, appressed pale short hairs, or at most with some on first two abdominal segments - Wings hairy throughout, not or scarcely papillate near tips (1)
Ericrocidini vs selected other genera
 Others - Middle tibial spur POINTED - Scopa present or absent (39)
 Ericrocidini - Middle tibial spur NOTCHED, bifid or multidentate at tip - Scopa ABSENT (4)
Ericrocis vs Mesoplia
 Ericrocis - Metasomal or tergal vestiture forming black and white to tawny broken bands - Mostly southwest, although Ericrocis lata occurs in east (1)
 Mesoplia - Metasomal vestiture including green or blue metallic scales or if not then the integument is green or blue - Only known from Arizona in the US, although its range extends southward through Mexico into parts of the West Indies and South America (1)
Eufriesea vs Eulaema
 Eufriesea - Face METALLIC at least slightly, clypeus lacking white markings - Clypeus variable, usually without a raised, longitudinal ridge - Labial palpus FOUR-segmented (1)
 Eulaema - Face non-metallic, commonly with WHITE markings on the clypeus - Clypeus with a strongly-raised, medial ridge running longitudinally - Labial palpus TWO-segmented (1)
Euglossa vs Eulaema
 Euglossa - Labrum, mandible, and lower portion of clypeus whitish - Body usually brilliantly metallic - Posterior tibia of male with hairy groove not reaching rounded apex of tibia - Middle tibia of male with one to three minute patches of velvety hairs at the end of the large patch of velvety hairs - Currently only in FL in the US (1)
 Eulaema - Labrum, mandible, and lower portion of clypeus dark, body usually black or weakly metallic, but sometimes brilliantly so - Posterior tibia of male with hairy groove reaching apex of tibia between two strong teeth or spines - Middle tibia of male with one elongate velvety patch adjacent to or within the larger patch - Rare in southernmost TX, also recorded from AZ in the US (1)
Eulonchopria vs Ptiloglossa
 Eulonchopria - Forewing with STIGMA LARGE, at least longer than the prestigma and usually also wider than the prestigma - The propodeal triangle is deeply and obviously pitted - MALE with outer hind tibial spur absent - Light colored INTEGUMENTAL bands present apically on at least some terga, but lacking any apical hair bands - Much SMALLER in direct comparison, ranging from 8-11mm according to Bees of the World (1)
 Ptiloglossa - Forewing with STIGMA SMALL, shorter than prestigma and about as wide as it - The propodeal triangle lacks pits, instead usually finely tessellate throughout - MALE with outer hind tibial spur immovably fixed in place, not articulated as spurs normally are - Terga often appearing more transparent or lighter along the rim, but LACKING distinct integumental bands of color and often having apical hair bands - Much LARGER in direct comparison, ranging from 15-20mm according to Bees of the World (1)
Exomalopsis and Anthophorula vs Oreopasites
 Exomalopsis and Anthophorula-Jugal lobe of hind wing at least 1/3 as long as vannal lobe, scopa well developed on hind tibia and basitarsus, labrum much broader than long (2)
 Oreopasites-Jugal lobe of hind wing less than 1/3 as long as vannal lobe, scopa ABSENT, labrum much broader than long, rare, west only (1)
Exomalopsis and Anthophorula vs selected other genera
 Others - Length of stigma LESS than 3 times as long as the length of the prestigma - Wing tip end of marginal cell gradually bent away from wing margin (19)
 Exomalopsis and Anthophorula -Length of stigma 3 or MORE times as long as the length of the prestigma, except in some Exomalopsis in which the wing tip end of marginal cell is bent abruptly away from wing margin (3)
Exomalopsis, Anthophorula, and Oreopasites vs. Neopasites, Rhopalolemma, and Townsendiella
 Exomalopsis, Anthophorula and Oreopasites-Apex of marginal cell bent sharply away from wing margin so that it is obliquely truncate, mandible simple (3)
 Neopasites, Rhopalolemma, and Townsendiella-Apex of marginal cell gradually bent away from wing margin and either pointed or narrowly rounded, mandible usually with one or more teeth (3)
Female Agapanthinus vs Other selected genera
 Others-Tibial spurs strong with middle spur more than half as long as tibia, lateral arm of hypostomal carina weak, T3 and usually T2 without basal pale pubescent bands or with a distal pale band in addition or entirely covered with pale pubescence (3)
 Female Agapanthinus-Tibial spurs weak with those on the middle leg less than half as long as tibia, lateral arm of hypostomal carina prominent, T2 and T3 with short dense white pubescence in broad basal bands with short relatively simple dark appressed hairs from basal bands almost to apices of terga, very rare, California and Baja California (1)
Female Andrena vs. Female Megandrena
 Andrena - Hind basitarsus more than half as long as hind tibia stigma often broader than prestigma occurs in east and west (1)
 Megandrena - Hind basitarsus about half as long as hind tibia stigma about as wide as prestigma rare occurs in southwestern US (1)
Female Eucera vs Female Simanthedon
 Female Eucera-Middle ocellus not as broad as flagellar width or as wide as flagellum, maxillary palpus six segmented, pygidial plate rather broad and rounded apically with apicolateral margins convex (1)
 Female Simanthedon-Middle ocellus broader than flagellum, maxillary palpus five segmented, pygidial plate tapering and bluntly pointed with apicolateral margin concave, rare, Southwest (1)
Female Melissoptila vs Other selected genera
 Others-Prestigma as long or longer than stigma, lateral hind coxal carina absent or reduced to short apical portion being straight or only slightly curved toward rear, maxillary palpus four to six segmented (2)
 Female Melissoptila-Prestigma shorter than stigma, lateral hind coxal carina sharp and bent strongly posteriad basally to form a rounded angle of almost 90 degrees, maxillary palpus two or three segmented, Tropical to Texas (1)
Female Syntrichalonia vs Other selected genera
 Others-Vertex weakly elevated if at all, median ocellus near or on summit or top of head in facial view, gradulus of T6 with lateral parts with a raised line or lamellate, scopal hairs with 6-8 branches on each side of the rachis rarely with as many as 10, apical part of rachis long extending beyond last branch by at least several average length of branches (4)
 Female Syntrichalonia-Vertex strongly elevated, median ocellus below summit or top of head in facial view, gradulus of T6 with lateral parts with a raised line, hairs of upper and outer parts of scopa with abundant uniform short branches mostly 10 or more branches on each side and often as many as 15, apical part of rachis extending beyond last branch usually shorter than the average length of the branches, southwestern (1)
Female, Ancylandrena vs. Andrena and Megandrena
 Andrena and Megandrena - Anterior surface of T1 with small concavity or groove, shorter than or only slightly longer than dorsal surface of T1 (2)
 Ancylandrena - Anterior surface of T1 concave, much longer than the length of the dorsal portion of T1- Rare, occurs in southwestern US only (1)
Female, Ancyloscelis vs Gaesischia - This character is specific to the North American species of these two genera, although these states may partially apply to some Central or South American species
 Ancyloscelis - The clypeus is highly protuberant, similar to many Eucerini, the distance from the compound eye to the clypeal rim clearly greater than half the length of the scape, often nearly equal to its total length - Vertex rounded, appearing evenly convex through its width - Dorsal area of the propodeal triangle bare of hairs, appearing finely tessellate, marked with microscopic lines - Tibial scopa composed of at least half BLACK hairs - Terga with DISTINCT white apical hair bands, the basal areas with only scattered darker hairs (1)
 Gaesischia - The clypeus is only slightly protuberant, if at all, with the distance from the compound eye to the clypeal rim being at most half the length of the scape, often shorter - The vertex is slightly concave to either side of the elevated ocellar area - Dorsal area of the propodeal triangle covered in long, dense whitish hairs which make it somewhat difficult to see the relatively smoother surface beneath - Tibial scopa composed of ENTIRELY LIGHT, whitish hairs - Terga with less distinct white apical hair bands, this due to the large amount of dense, light hairs present in the basal area of the terga, this most obvious from T3 onward to the tip of the abdomen (1)
Female, Augochlora vs Augochlorella
 Augochlora - Marginal cell distinctly although narrowly SQUARED-OFF or TRUNCATE at tip - Lateral margin of the clypeus where it joins the paraocular area with a rounded lobe or peninsula that extends down at an acute angle into the clypeus - Ends of mandibles forked with two dark slightly pointed tips that are nearly equal in length (1)
 Augochlorella - Marginal cell with apex pointed on wing margin - Lateral margin of the clypeus where it joins the paraocular area a simple right angle similar to most other bee species - Ends of mandibles with rounded, slightly reddish, tips with a second tooth located on the upper side just back from the tip, giving the general look of a mitten, similar to many other halictid species (1)
Female, Cemolobus vs selected other genera
 Others - Rim of clypeus squared-off, uniformly straight or slightly convex (17)
 Cemolobus - Rim of clypeus, when viewed from above, tri-lobed, central, median lobe short and broad and often slightly concave - A very rare bee (1)
Female, Eucera and Simathedon vs Other selected genera
 Others-Clypeus flat to slightly protuberant, postpalpal part of galea not longer than eye (5)
 Female Eucera and Simanthedon-Clypeus protuberant, postpalpal part of galea longer than eye (2)
Female, Eucera vs Tetraloniella
 Eucera, postpalpal part of galea longer than eye. clypeus protuberant - slightly less so than in male (2)
 Tetraloniella, Postpalpal part of galea not longer than eye. clypeus flat to slightly protuberant - slightly less so than in male (1)
Female, Florilegus vs Tetraloniella
 Florilegus - Leg, basitibial plate with margin entirely exposed, surface often bare - Abdomen, T6 with lateral parts of gradulus lamelliform, narrowing to a thin and plate-like squared-off end with sharp tooth-like corners (1)
 Tetraloniella - Leg, basitibial plate hidden by hairs, with front and the end towards tip of margin hidden, surface usually hairy - T6 with lateral parts of gradulus cariniform, never toothed or squared off, some species tend towards thin plate-like narrowed ends (1)
Female, Melissodes vs selected other genera
 Others, tegula not narrowed towards front, outer front margin rounded, convex (15)
 Melissodes, tegula narrowed towards front, outer front margin flattened, slightly concave or straight - note that hairs often have to be scraped away in order to see this feature (2)
Female, Peponapis vs Xenoglossa
 Peponapis - Base of mandibles, clypeus and labrum all DARK (1)
 Xenoglossa - Base of mandibles and to more variable extent clypeus and labrum with clearly YELLOW markings (1)
Female, Peponapis vs selected other genera
 Others - Mandible simple without a notch or subapical tooth at the tip - The hairs on the inner surface of the basitarsus of the hind leg relatively uniform and usually dense enough that the surface is obscured (11)
 Peponapis - End of mandible with a distinct notch or tooth at the tip, this notch is relatively shallow and in older individuals the mandible can be worn away so much that the notch is gone - The hairs on the inner surface of the basitarsus of the hind leg are composed of two types, one type is very long and sparse, sparse enough that the surface is clearly visible and the other type of hair forms a narrow band of very short and very dense hairs running down the segment near the posterior margin - When viewed from the side, the clypeus is prominent, protruding outward about the same distance as the eye is wide (1)
Female, Svastra vs selected other genera
 Others, maxillary palpus five- or six-segmented. base of second abdominal segment hairs without spoon-shaped tips. lateral arms of gradulus of top sixth abdominal segment cariniform to lamelliform (1)
 Svastra, maxillary palpus usually 4-segmented. if maxillary palpus 5-segmented, then base of second upper abdominal segment with at least a few branches of hairs with flattened spoon-shaped tips. lateral arms of gradulus of top sixth abdominal segment lamelliform, often with a small tooth (1)
Female, Xenoglossa vs selected other genera
 Others, Inner margin of mandible without basal tooth (13)
 Xenoglossa, Inner margin of mandible with tooth near base - careful, tooth points slightly inward and if mandible tightly closed it cannot be seen (1)
Female, abdomen, pygidial plate - The raised plate on T6 may sometimes be hidden beneath the rim of T5 if T6 is retracted
 Present, but variable in shape, clearly elevated such that it appears to sit above the integument of T6 (104)
 Absent, but sometimes with a bare or differently patterned region at the tip of T6, if so then this area is not raised and clearly elevated above the remainder of the integument (74)
Female, head, face, fovea
 Absent (131)
 Present - pay attention, they can be very narrow (11)
Female, head, face, presence of NON-METALLIC white, yellow, or red surface markings on the integument when NOT INCLUDING the antennae, labrum or mandibles
 Absent (150)
 Present (65)
Female, head, mandible, number of teeth - Note that a tooth here is defined as any projection along the UPPER surface of the mandible, THE TIP OR END THE MANDIBLE COUNTS AS A TOOTH and can be either pointed or rounded - DO NOT USE this character if your specimen has worn mandibles
 2. TWO teeth - With either a subapical rounded tooth or a strong projecting angle within the apical third of the length of the mandible, usually set back behind the tip of the tooth, and rarely with what would appear to be a forked tip to the mandible, ignore small bumps or angles that uncommonly occur near the base of the mandible in some species, as this focuses on those within the apical third and basal teeth or projections are too often hidden when the mandibles are closed (80)
 1. ONE tooth - Simple, with only a single apical point which does not have any subapical tooth or angle in the apical third of the length of the mandible, although more basally there may some such tooth or angle (60)
 3. THREE teeth - Mandible with three WELL-DEFINED teeth found anywhere along the length of the upper portion of the mandible, these teeth may have complete or partial knife-like cutting edges running between and lower than the tips of the teeth in some Megachilidae these cutting edges to not count as teeth (28)
 6. FLARED OUT AT TIP, UNTOOTHED OR ONLY TOOTHED NEAREST TO CLYPEUS - The mandibular cutting edge where teeth are normally present is largely flat and unmodified, although the tip farthest from the clypeus still usually comes to a point apically - Note that this is different than a simple mandible because this cutting edge is very long like you would expect from a megachilid bee, but instead of having teeth the cutting edge is flat for its entire length or nearly so, if with ANY teeth then they are at the basal corner of the cutting edge nearest to the clypeus and are NOT present in the apical half of the cutting edge toward the tip (24)
 4. FOUR teeth - Mandible with four WELL-DEFINED teeth found anywhere along the length of the upper side of the mandible, these teeth may have complete or partial knife-like cutting edges running between and lower than the tips of the teeth them in some Megachilidae these cutting edges to not count as teeth (20)
 5. With five or more distinct teeth (8)
Female, hind leg, basitibial plate, presence or absence - Be careful as dense hairs may sometimes obscure this plate
 Absent (92)
 Present (74)
Female, hindleg, tibia, presence or absence of a corbicula
 Absent, hind tibia either with hairs throughout its outer surface or without hairs but not broadly flattened with long hairs around the perimeter (141)
 Present, the outer face of the rear tibia appearing broadly flattened and HAIRLESS, usually with long hairs around the perimeter of the hairless area (21)
Female, leg, hind pair, scopa
 Scopal hairs on hind legs simple or with barbs so minute that they are visible only under close scrutiny under high power (19)
 Scopal hairs on hind legs with branches off the main hair that, while often fairly short, are clearly visible under moderate microscopic powers (15)
Female, leg, pollen carrying hairs, location - Note, lots of variability in density and type of pollen carrying hairs, can be tricky to determine, see explain for details
 ADMIN ONLY - ALL (160)
 On tibia (93)
 On femur (44)
 No scopa present (40)
 Underside of abdomen (29)
Fore leg, basitarsus, presence and location of a dense, LINEAR brush of hairs which appears thickened such that it is comb-like - Note that a fringe of long, obviously separated hairs is not considered a comb here
 Absent - Although hairs are nearly always present, they are not arrayed in a line such that they line up like a comb of unusually thick hairs (157)
 Present, located along the INNER AND-OR REAR edge of the basitarsus and running along its length - Often but not always the brush is somewhat weakly formed and light may be visible through it (4)
 Present, located along the OUTER FRONT edge of the basitarsus and running along its length - The comb is extremely dense and almost appears to be made of integument rather than dense hairs (1)
Frieseomelitta vs Tetragona
 Frieseomelitta - Labial palpi with long, sinuous hairs present on the first two segments, these hairs often numbering more than 20 - In direct comparison, usually smaller, ranging from 4-6.5mm according to Bees of the World - Within nests, brood cells are arranged in clusters (1)
 Tetragona - Labial palpi with no hairs that are longer than the width of the palpus at the point of origin of the hair, those hairs present being straight or nearly so - In direct comparison, usually larger, ranging from 5-8mm according to Bees of the World - Within nests, brood cells are arranged in combs (1)
Geotrigona vs Oxytrigona
 Geotrigona - Face normal, with the minimum distance between the compound eyes less than or equal to the height of the eye and rarely, if ever, greater - Female malar space small, usually equal to less than half the basal width of the mandible - Clypeus less than twice as broad as it is long (1)
 Oxytrigona - Face abnormally broad, the minimum distance between the compound eyes clearly greater than the length of the eyes themselves - Female malar space long, exceeding half the basal width of the mandible and often nearly equal to the full width - Clypeus usually more than twice as broad as it is long (1)
Geotrigona vs other selected genera
 Other selected genera - Face with or without yellow markings - Forewing with vein M usually becoming indistinct around the widest point of the wing - Abdomen usually much thinner than the thorax - Hind tibia with many branched hairs present at the base, these hairs usually with many branches near their apices (2)
 Geotrigona - Face lacking any yellow markings - Forewing with vein M appearing distinct nearly to the wing margin - Abdomen short and stout, about as wide as thorax and appearing somewhat dorsoventrally flattened - Near the base of the hind tibia, there are very few branched hairs, those that are branched often with few branches near the apex (1)
Habralictus vs Mexalictus
 Habralictus - The male abdomen is very slender throughout, much longer than wide in at least T1-2 - The female paraocular area does not extend onto the clypeus, the suture forming its border with the clypeus here forming at most an obtuse angle - The female usually has a basal yellow integumental band or lateral spots on the terga, although in some species this is not present - This genus is recorded from southern Mexico near Guerrero down into much of South America (1)
 Mexalictus - The male abdomen is of normal width throughout - The female paraocular lobe protrudes into the margin of the clypeus, the suture between it and the clypeus forming a lobe nearly as prominent as is seen in some Augochlorini and clearly forming an acute angle - The female abdomen lacks yellow integumental markings - These species generally resemble members of the Lasioglossum subgenus Dialictus, although their unweakened submarginal cell veins allow easy differentiation - This genus is only known from the southwest US down into Panama (1)
Halictus vs Lasioglossum - Two very common genera
 Halictus - RIMS of T2 and T3 USUALLY covered by a complete, uniform, dense band of prone short pale hairs, note that at times this can be worn away in the center and thus they will appear only on the sides - All transcubital veins of the submarginal cells the same thickness (1)
 Lasioglossum - T2 and T3 with either no dense bands of PRONE short pale hair at all or that band is located at the BASE of the segment, often appearing to come out from UNDERNEATH the rim of the preceding segment, in the green and bluish species this band is often just a short patch of white hairs on the sides, at times there may be something that looks like a thin hair band on the rim, but the hairs are very thinly spaced and not short and thick - Outermost transcubital vein weakened IN FEMALES, this character hard to discern in some males, appearing to be much fainter than the other veins of the wing, at high magnification this can appear like a single faint line while the other veins appear as 2 parallel lines, in some smaller species both the 2nd and the 3rd veins are weakened (1)
Halictus vs Mexalictus
 Halictus - Paraocular lobe only obtusely protruding into the clypeus, if at all - Terga with distinct, light hair bands present along the apical rim - In direct comparison, with much more robust bodies (1)
 Mexalictus - Paraocular lobe protruding down onto the clypeus acutely or almost acutely, as is seen in some Augochlorines - Hairs of terga scattered, not forming apical hair bands - In direct comparison, much more slender, appearing similar to some thinner Lasioglossum in terms of body shape (1)
Halictus vs Sphecodes
 Halictus - The female labrum has a central longitudinal raised keel running along the narrowed process or tip of the labrum - Scopa present on hind femur in females - Males with distinct apical hair bands lining the rim of the tergites - Integument of abdomen black or sometimes dark and dull metallic greenish - Overall, usually much less roughly sculptured and pitted throughout the thorax (1)
 Sphecodes - The female labrum is simple and usually unkeeled, if with any sort of raised line or keel is present then only very weak - A nest parasite, so scopa are absent in females - Males with no dense bands along the rims of the tergites - Integument of abdomen often RED primarily or entirely, although in some species, particularly males, it may be black - Overall, usually much more strongly pitted and sculptured throughout its body (1)
 Sphecodes - Clypeus and legs always entirely black - Tergites never with hair bands along the rim, those hairs that are present appearing scattered (1)
Halictus vs other selected genera
 Other genera - Combination not as above (4)
 Halictus - Both females and males have light-colored apical hair bands on the terga - The compound eyes DO NOT strongly converge below, usually about parallel or only slightly convergent - There are no integumental yellow markings on the abdomen - Male abdomen of normal width and not appearing much more slender basally than apically, T1 almost always wider than long - Female T5 appears more hairy at the rim than on T4 - Body either dull black or sometimes with relatively weak metallic reflections, NOT approaching the type of bright green seen in many Augochlorini (1)
Head, compound eyes, presence or absence of scattered and obvious hairs
 Absent (135)
 Present (10)
Head, labral process, shape - DO NOT count the sometimes dense hairs present at the apex of the labrum as part of its length. Note - Longitude refers to distance along the length or long axis of the bee and Latitude refers to the distance across the width of the bee
 1. BROAD - Latitudinal distance greater than longitudinal distance (117)
 3. LONG - Longitudinal distance greater than latitudinal distance (59)
 2. EQUAL - Latitudinal and longitudinal distances about equal (50)
Head, mouthparts, long-tongue vs short-tongue bees - A very useful character but often unusable if the mouthparts are not visible
 Long-tongue bees - On the labial palpus the first two segments are elongate and usually at least somewhat flattened, contrasting with the much smaller and less flattened terminal segments of the palpus, these terminal segments often pointed laterally in repose, such that they usually form an angle around 90 degrees or sometimes less - The stipital comb, a comb of hairs located near the apex of the stipes that is found within a slight concavity, is usually, but not always, present - Galeal comb absent or, rarely, very weak - Galeal blade normally elongate, most often equal or greater than the stipes in terms of length (106)
 Short-tongue bees - On the labial palpus the four segments are usually of similar size, although sometimes the first segment may be elongate and VERY rarely the second segment may be as well, in these cases the segments are not flattened as greatly as in the long-tongue bees - Stipital comb and concavity ALWAYS absent - Galeal comb commonly present - Galeal blade usually distinctly shorter than stipes (56)
Head, number of subantennal sutures - Note that in some species the inner suture may be weak or partially indistinct, so care should be taken
 1 (146)
 2 (14)
Head, tongue, glossa, tip shape
 Simple, pointed or rounded, although usually pointed (154)
 Bilobed or emarginate, either divided into two distinct parts which diverge from one another and come to independent tips or broadly flattened at tip with a dip in the center (8)
Heriades vs selected other genera
 Others, base of propodeum not separated from rear surface by raised line and without a series of strong pits - if carina and pits evident, basal zone usually sloping and front upper surface of first abdominal segment - T1 - not concave and surrounded by a raised line (9)
 Heriades, propodeum with a narrow horizontal line of very large squarish pits just below the metanotum, set off by ridge from rear surface. front surface of upperside of first abdominal segment broadly concave and surrounded by a strong ridge or raised line (1)
Hesperapis vs Macropis
 Hesperapis, hind basitarsus of both sexes thinner than, and nearly as long as, hind tibia (1)
 Macropis, hind basitarsus of male less than half as long as tibia, in females shorter than and as broad as tibia (1)
Hexepeolus and Triopasites vs. Nomada and Brachynomada
 Nomada and Brachynomada - Apical portion of marginal cell on wing margin or nearly so - Terga without pubescent or hairy bands (2)
 Hexepeolus and Triopasites - Apical portion of marginal cell bent away from wing margin - Terga with pubescent bands (1)
Hexepeolus vs Triopasites
 Hexepeolus - Strong white apical hair bands present on the tergites, these bands dense enough to obscure the surface of the integument and very narrowly interrupted at the center - Female S6 with a large, rounded lobe, directed posteriorly, to each side of a deep medial emargination - In direct comparison, a much blacker bee, with only some slight reddening of the legs and abdomen present sometimes (1)
 Triopasites - Weak white apical hair bands present, the integument clearly visible through the hair band, usually weakest on T2 where the band is widely interrupted by about half the latitudinal width of the rim or more - Female with end of S6 apically strongly forked in the center of the rim, the two tips appearing distinctly pointed and either rod like or made up of several spines - In direct comparison, a much more overall red bee, the abdomen usually entirely red along with the legs and much of the thorax, although sometimes there may be some blackening throughout (1)
Hoplitis vs Protosmia
 Hoplitis - Female clypeus variable, usually slightly concave medially, but not with a strongly-projecting spatulate process apicomedially - The anterior face of T1, which faces the vertical face of the propodeum, is broadly convex such that it appears about evenly rounded in profile (1)
 Protosmia - Female clypeus with an apicomedial spatulate projection - The anterior face of T1 is broadly concave, the border between the anterior face and the dorsal face represented by a line that is well-defined at least medially (1)
Hoplostelis vs Hypanthidioides
 Hoplostelis - Female mandible USUALLY with a jutting angle or projecting corner along its lower edge near the base, although in some species it may appear as just a bump - Parasitic species, female scopa absent on underside of abdomen - Male T7 only weakly bilobed, if at all, this segment smaller and at times hidden by T6, but if visible it is only equal to or slightly longer than T6 in length - In general, these bees are usually more compact in terms of body form - Most of these bees are larger in direct comparison, ranging from 8-14mm according to Bees of the World (1)
 Hypanthidioides - Female mandible normal, without a distinctly swollen or projecting angle near the base - Female scopa present on underside of abdomen - Male T7 strongly bilobed apically and larger, such that it is always clearly jutting beyond T6 and often appears much longer than T6 itself - In comparison, these bees are, on average, more elongate - In direct comparison most of these bees are smaller in size, ranging from 5-9mm according to Bees of the World (1)
Hylaeus vs selected other genera
 Others, jugal lobe of hind wing less than one-fourth as long as vannal lobe (2)
 Hylaeus, jugal lobe of hind wing about three-fourths as long as vannal lobe (1)
Hypanthidioides and Hypanthidium vs Pseudoanthidium
 Hypanthidioides and Hypanthidium - The terga are pitted to within a pit diameter or two of their rim, making the rim often appear to lack the standard impressed portion or to be clearly differentiated from the rest of the tergite - The hairs along the rim of S3 are generally about equal in length throughout, weakly curved or straight in appearance, although in some species they may appear longer, but non-wavy, medially - The rim of S5 in males appears straight or nearly so, sometimes with a medial comb of hairs (2)
 Pseudoanthidium - The impressed apical rim of the terga are unpitted for about 3-4 pit diameters, with this area appearing slightly angled upward in relation to the anterior majority of the terga in a lateral view - S3 of the males with a medial comb of long, very wavy hairs which project out in comparison to the hairs elsewhere along the rim - S5 in males is slightly concave or emarginate, with at least one linear comb of hairs found along the rim to each side (1)
Hypanthioides vs Hypanthidium
 Hypanthidioides - Juxtantennal carina present, just above the antennal fossa there is a ridge which travels downward along the inner side of the fossa before diverging from it, this happening usually near the midpoint of the fossa or earlier - With or without arolium, although usually without - Usually smaller than Hypanthidium in direct comparison, ranging from 5-9mm according to Bees of the World (1)
 Hypanthidium - Juxtantennal carina absent, face evenly sculpted along the inner margin of the antennal fossae - Always without arolium - Usually larger than Hypanthidioides in direct comparison, ranging from 7-15mm according to Bees of the World (1)
Lasioglossum vs Nesosphecodes
 Lasioglossum - Wing venation distinctly weakened in at least the third transcubital vein, often in the second transcubital vein as well, the weakened vein appearing to be a single line when viewed under 20X or greater power (1)
 Nesosphecodes - Wing venation equally strong in all three transcubital veins, these veins each appearing, at 20X or greater power, to be composed of 2 lines (1)
Lasioglossum vs Ptilocleptis
 Lasioglossum - Forewing with at least the outermost transcubital vein weakened, appearing as a single line when viewed under magnification, although this is harder to tell in male specimens - Scopa almost always present, only absent in some few rare parasitic species (1)
 Ptilocleptis - Forewing with all transcubital veins equally strong, each side of the vein appearing as a darkened border - Scopa always absent (1)
Lasioglossum vs Sphecodes
 Lasioglossum, third transverse cubital and second recurrent veins weaker, thinner than nearby veins, most apparent in females. scopa on femur distinct unless one of the rare parasitic members. body only rarely coarsely sculptured. head narrow to moderately broad in frontal view (1)
 Sphecodes, wing venation uniformly strong. scopa absent. body, and especially base of propodeum, coarsely sculptured. head conspicuously broad in frontal view (1)
Leg, arolium - A pad-like structure that rests between the two claws
 Present - although sometimes minute and usually also associated with long hairs (133)
 Absent - look closely, while there may be no pad there is often a clump of hairs present (24)
Leg, claws, shape
 Cleft or with inner tooth (65)
 Simple, no teeth or cleft (19)
Leg, middle pair, tibia, spines on end nearest tarsi
 With one spine or no distinct spine. scopa of female usually present on underside of abdomen, except in Hoplostelis (17)
 With two spines on outer side - for small specimens examine from top. scopa of female absent (1)
Leiopodus vs Mesoplia
 Leiopodus - Tibial spur of midleg with a tip that is NOT bifurcate, with only one tip as in most bee genera - Legs brown, black, or sometimes reddish orange - Abdomen black or brownish - Most often with latitudinally COMPLETE OR NARROWLY INTERRUPTED light hair bands, when these hair bands are interrupted the gap is less than half of the latitudinal width of the tergite (1)
 Mesoplia - Tibial spur of midleg with TWO DISTINCT TIPS, one of which is clearly longer than the other - Legs most often with some blue or greenish metallic reflections - Abdomen with obvious BLUE OR GREEN integumental coloration that has at least some metallic reflection, although in some species it is only slight - If with any light hair patches on the terga, they are usually WIDELY interrupted such that more than half the latitudinal width of the terga is bare (1)
Leiopodus vs Other selected genera
 Others-Pygidial plate distinct in females and most males, basitibial plate distinct in females and most males, scopa present on hind tibia and basitarsus, patches of appressed plumose hairs absent although hair bands are commonly present (16)
 Leiopodus-Pygidial plate absent or modified as to be unrecognizable in both sexes, basitibial plate absent, scopa absent, terga with patches of appressed plumose hairs, rare, Southwest (1)
Length of F1 vs F2 and length of F11 of antenna in MALES of selected genera
 Maximum length of F1 usually much less than length of F2, or if about the same then F11 less than twice as long as broad and rounded apically (3)
 Maximum length of F1 of antenna as great as or slightly greater than minimum length of F2, F11 at least twice as long as broad (1)
Length of FEMALE bee - Use With Caution, measurements taken directly from Mitchell, your measurements may differ from his
 10 (90)
 9 (89)
 7 (85)
 8 (85)
 11 (82)
 6 (82)
 12 (77)
 13 (73)
 5 (66)
 14 (62)
 15 (55)
 4 (50)
 16 (47)
 17 (40)
 18 (34)
 3 (30)
 19 (26)
 20 (22)
 21 (14)
 22 (14)
 2 (10)
 23 (10)
 24 (10)
 25 (9)
 26 (7)
 1 (6)
 27 (5)
 28 (4)
 29 (2)
Length of MALE bee - Use With Caution, measurements taken directly from Mitchell, your measurements may differ from his
 7 (93)
 8 (93)
 9 (92)
 10 (85)
 6 (81)
 11 (80)
 12 (75)
 5 (73)
 13 (69)
 14 (61)
 4 (56)
 15 (53)
 16 (43)
 17 (35)
 3 (33)
 18 (28)
 19 (19)
 20 (17)
 2 (13)
 21 (12)
 22 (12)
 23 (10)
 24 (9)
 25 (8)
 1 (7)
 26 (7)
 27 (5)
 28 (2)
Lestrimelitta vs selected other genera
 Other genera - Female F1 clearly shorter than F2 plus F3, male F1 clearly shorter than F2 - Females with corbicula present, lower half of the outer face of the hind tibia distinctly more concave than the upper half - Males almost always with a medial projection on S6 - Size variable (15)
 Lestrimelitta - Female F1 nearly as long as F2 plus F3, male F1 nearly as long as F2 - Females with corbicula absent, outer face of hind tibia convex throughout - Males with a median notch on S6 - Size ranging from about 4-7mm, according to Bees of the World (1)
Lithurgopsis vs Lithurgus - Note that the former was originally a subgenus of Lithurgus and was recently elevated to genus status
 Lithurgopsis - Males differentiated by having arolia - For females, the outer hind tibial spur is thickened and strongly bent apically - For females, F1 is shorter, usually shorter than F2 but sometimes very slightly longer (1)
 Lithurgus - Males differentiated by having no arolia - For females, the outer hind tibial spur is thinner and at most very weakly bent - For females, F1 is longer, usually about twice as long as F2 (1)
Lithurgus vs other selected genera
 Other, mandible a simple blade or with lower tooth longest, number of teeth variable. outer surface of tibia, if spiculate, with a bristle arising from apex of each, except in some parasitic forms that lack scopa and have labrum broader than long (29)
 Lithurgus, mandible with three teeth with middle tooth longer and more elevated than the others, outer surface of tibia at least in female with numerous coarse spicules not bearing hairs or bristles, labrum longer than broad (2)
Location of antennal bases on bee face, in relation to the distance from the top of the head to the apex of the clypeus, not including the mandibles
 Others - Antennal bases near middle of face as in most bees, or, if below, separated from clypeus by much more than distance of an antennal socket - Clypeus with upper margin strongly arched up into the face so that it is not short and wide - Labrum, excluding apical process, if any, much shorter than clypeus - Pre-episternal groove ABSENT below scrobal groove, however, this is difficult to see (33)
 Antennal bases well BELOW middle of face and separated from clypeus by not much more than the diameter of an antennal socket - Clypeus SHORT AND WIDE, its upper margin not much arched up into the rest of the face - Labrum nearly as long as clypeus - Pre-episternal groove PRESENT-Dufourea is the only genus with this condition in the east and it is quite rare (5)
Macrotera and Perdita vs other selected genera
 Other selected genera - Marginal cell relatively LONG, usually clearly occupying more than half the distance from the tip of the marginal cell to the apex of the wing along the length of the margin of the wing - Hind tibia of male most often, but not always, toothed or at least carinate on the upper margin (6)
 Macrotera and Perdita - Marginal cell unusually SHORT, the distance the marginal cell extends along the margin of the wing is approximately half that of the distance from the wing tip to the tip of the marginal cell - Most often with two submarginal cells, but sometimes with one or when with three cells with the second cell reduced to a small triangle - Second submarginal cell, the third if with the small second intermediary cell, short, with its greatest length USUALLY less than two-thirds that of the first submarginal cell - Hind tibia of male only very rarely toothed on the upper margin (2)
Macrotera vs Perdita
 Macrotera-Stigma slender being little if any broader than prestigma, outer groove of mandible narrow basally similar to how it is apically and bent upward and cutting diagonally across the mandible, episternal groove absent or short not curving posteriorly, body nonmetallic with the yellow maculations usually absent except for the face although body is commonly honey colored and terga are frequently red at least in males, occurs in west only (1)
 Perdita-Stigma large in most species, outer groove of mandible broadened and fading away toward the base, episternal groove usually curving posteriorly, occurs in east and west although much more diverse in the west, typically associated with sand in the east (1)
Male Andrena vs. Male Ancylandrena
 Ancylandrena-Anterior surface of T1 concave with a median line or groove AND this surface longer than distance from its apex to the apex of T1 hind basitarsis less than five times as long as wide rare, occurs in southwestern US (1)
 Andrena-Anterior surface of T1 largely convex, the concavity a median groove or depression that is shorter or only slightly longer than distance from its apex to the apex of T1 hind basitarsis five or more times as wide occurs in east and west (1)
Male Martinapis vs Male Agapanthinus, Gaesischia, and Tetraloniella
 Male Agapanthinus, Gaesischia, and Tetraloniella-F1 of antenna half as long as F2 or less, F11 not tapering although pointed and hooked in Agapanthinus, flagellum tan to black (2)
 Male Martinapis-F1 of antenna only slightly shorter than F2, F11 tapering to apex, flagellum bright yellow, rare, Southwest (1)
Male Megandrena vs. Male Andrena and Male Ancylandrena
 Andrena and Ancylandrena-Mandible with tooth on upper margin gonobase with a broad dorsal surface (2)
 Megandrena-Mandible simple or with a very weak preapical tooth gonobase a narrow ring or essentially absent rare, occurs in southwestern US (1)
Male Melissoptila vs Male Florilegus, Melissodes and Peponapis
 Male Florilegus, Melissodes and Peponapis-Stigma small usually as short as or shorter than prestigma, maxillary palpus usually four or five segmented rarely three segmented, lateral hind coxal carina reduced or absent (3)
 Male Melissoptila-Stigma slightly longer than prestigma, maxillary palpus two or three segmented, lateral hind coxal carina prominent, tropical to Texas (1)
Male Simanthedon vs Other selected genera
 Others-Clypeus uniformly convex or straight in profile (6)
 Male Simanthedon-Clypeus strongly protuberant and abruptly beveled and snoutlike apically with its profile forming a distinct preapical angle and concave above the angle (1)
Male Syntrichalonia vs Male Svastra in part, formerly Anthedonia
 Male Svastra in part-S1 relatively flat without a prominent median convexity, F11 of antenna tapering and acuminate apically, this particular group rare (1)
 Male Syntrichalonia-S1 with a prominent median convexity directed posteriorly and with a small deep impression on either side near the apex, F11 of antenna rounded apically, uncommon, southwestern (1)
Male, Agapostemon vs selected other genera
 Others - Thorax and head nonmetallic or weakly metallic greenish or bluish, at times mixed with gold or brass overtones (2)
 Agapostemon - Thorax and head bright green or blue (1)
Male, Anthophora vs Melecta
 Anthophora - Marginal cell clearly longer than 3rd submarginal cell - Scutellum not modified (1)
 Melecta - Marginal cell slightly less than to about the same length as the 3rd submarginal cell - Scutellum with 2 extraordinary, unmistakable, hairy, cone-like projections on the far sides (1)
Male, Augochlora vs Augochlorella
 Augochlora - Tip of marginal cell narrowly but distinctly truncate - Rim edge or margin of S4 completely straight across (1)
 Augochlorella - Tip of marginal cell unmodified, smoothly rounded to edge of wing - Rim edge or margin of S4 noticeably concave (1)
Male, Caupolicana vs Zikanapis
 Caupolicana - LONG hair present at the lateroventral corners of T2-5, past the downward bend around the sides of the abdomen - S6 most often BROADLY ROUNDED along the rim, rarely with a V-shaped notch present medially, but if so then the rim is not produced as much as in Zikanapis (1)
 Zikanapis - Dulled, scarcely-pitted areas present at the lateroventral corners of T2-5 past the downward bend around the sides of the abdomen, these areas at most with very SHORT and dense hairs of uniform length - S6 with an apicomedial projection that has a distinct V-SHAPED NOTCH, although the projection may sometimes appear weak (1)
Male, Cemolobus vs selected other genera
 Others, rim of clypeus squared-off. first flagellar segment usually shorter than second. bottom sixth abdominal segment usually without lateral teeth (14)
 Cemolobus, clypeal margin trilobed, median lobe broad, often with a shallow concave margin. first flagellar segment as long as second. bottom, sixth abdominal segment with a large, laterally directed, lateral tooth (1)
Male, Emphorini vs Eucerini
 Eucerini - Males usually with much LONGER antennae, when held at rest over the bee they usually extend well beyond the tegulae and near the end of the abdomen - In direct facial view, the vertex of the head appears variable, often with the middle of the vertex, behind the ocelli, disproportionately raised in comparison to the rest of the integument and the overall vertex appearing more FLATTENED and not uniformly convex (14)
 Emphorini - Males usually with much SHORTER antennae, when held at rest over the bee they usually extend no farther than the tegulae - In direct facial view, the vertex of the head appears evenly CONVEX throughout (4)
Male, Eucera vs Peponapis
 Eucera, Sixth underside abdominal segment almost always with oblique lateral apical carina curved outward and thickened basally, ending in a lateral blunt tooth or obtuse angle of the sternum. antenna usually long, reaching stigma in repose (1)
 Peponapis, sixth underside abdominal segment with oblique lateral apical carina straight, underside of abdomen without teeth or strong angles on sides. antenna of moderate length, not reaching stigma in repose (1)
Male, Florilegus vs other genera
 Others, underside of 6th abdominal segment flat or with an exceedingly shallow, longitudinal median depression. front femur broadest from base to middle (7)
 Florilegus, underside of 6th abdominal segment with a prominent raised area in the middle of the plate. front femur broadest about one-fourth or one-third of its length from apex (1)
Male, Melissodes vs Peponapis
 Peponapis - Tegula rounded, oval, not narrowed in front, with the outside margin convex - Clypeus strongly protuberant (2)
 Melissodes - Tegula narrowed toward anteriorly, front half to third of outside edge slightly concave or straight, often hidden by hairs - Clypeus little or moderately protruding, extending in front of eye by eye width or less in lateral view (1)
Male, Melissodes vs Xenoglossa
 Melissodes - First flagellar segment much shorter than second - Tegulae distinctly narrowed anteriorly, much wider at the rear than in the front half, although hairs may need to be removed to confirm this (1)
 Xenoglossa - First flagellar segment at least equal to second - Tegulae about equal in width near front and rear, somewhat bean-like in shape, not distinctly narrowed anteriorly (1)
Male, Peponapis vs Xenoglossa
 Peponapis - Base of mandibles DARK - First flagellar segment almost always several times SHORTER than second - Antennae generally longer, often reaching past the tegulae (1)
 Xenoglossa - Base of mandibles with clear YELLOW markings - 1st flagellar segment clearly LONGER than second - Antennae generally shorter, not reaching past the tegulae (1)
Male, Svastra vs other selected genera
 Others, maxillary palpus 5 -or- 6 segmented. T2 never with any hairs that are plumose at base and spatulate at tip - note, care must be taken to look at many hairs (2)
 Svastra, maxillary palpus usually 4-segmented, if 5-segmented, then upperside of 2nd abdominal segment - T2 - with a band of hairs that include at least a few that are plumose at the base and spoon-shaped at the tip (1)
Male, Tetraloniella vs selected other genera2
 Others, distance between edge of clypeus and edge of eye short to long, equal to one-third of minimum width of first flagellar segment or more (1)
 Tetraloniella, distance between edge of clypeus and edge of eye extremely short, never more than about one-fourth of minimum width of first flagellar segment (1)
Male, abdomen, T7
 Without lateral teeth - Occasionally S6 with lateral teeth that can be seen from above and may be confused (47)
 With lateral tooth or strong projecting angle on each side of the pygidial plate, if it is present - Note, sometimes hidden in dense hair or by the 6th segment (10)
Male, head, antennae, length - Note that measurements should be conducted with the antennae in natural repose, when they are arched backward over the head toward the abdomen
 1. Short, not unusually elongate, appearing similar to the antennae of the females of the species, not surpassing the posterior edge of the tegulae (129)
 2. Moderately long - The tips of the antennae reach about as far back as the tegulae or slightly longer, clearly not reaching the abdomen (119)
 3. Long - The tips of the antennae reach back past the end of the propodeum from a dorsal view, but not past the tip of the abdomen (31)
 4. Extremely long, the tips of the antennae reaching past the tip of the abdomen (6)
Male, head, face, presence of NON-METALLIC white, yellow, or red surface markings on the integument when NOT INCLUDING the antennae, labrum or mandibles
 Absent (123)
 Present (94)
Male, leg, rear pair, basitarsus
 Shorter than tibia (58)
 As long as or longer than tibia (4)
Male, middle leg, tibial spur size
 Tibial spurs weak, middle tibial spur about or less than half as long as tibia as measured from base of spur to joint of tibia and femur (6)
 Tibial spurs strong, middle tibial spur longer than length of half of tibia (4)
Male, wing, first recurrent vein
 Meeting second submarginal cell or intersecting with the second transverse cubital vein (39)
 Meeting the third submarginal cell (4)
Males, Xenoglossa vs selected other genera
 Others, first flagellar segment no longer than second segment and often much shorter. inner margin of mandible without tooth near base (10)
 Xenoglossa, first flagellar segment more than 1.5 times as long as second. inner margin of mandible with tooth near base - careful tooth points slightly inward and can be difficult to see when mandibles are tightly closed (1)
Megachilidae only - Head, vertex, presence of carina on the preoccipital margin
 ABSENT, the vertex appearing smoothly ROUNDED all the way to the rim (19)
 PRESENT, the vertex having an abrupt RIDGE along the back of the head which runs along most or all of the posterior rim of the head (9)
Megachilidae only - Rear legs, coxae, presence of a longitudinal carina
 Absent, the coxae are evenly rounded over (19)
 Present, there is a ridge running along the length of the coxae such that it appears divided (10)
Megachilidae only - Thorax, propodeum, presence of fovea posterior to propodeal spiracle
 Without fovea posterior to spiracle, the integument relatively evenly pitted or sculpted throughout the area (19)
 With fovea posterior to spiracle, a clear, roughly linear depression present and interrupting the pitting or sculpting of the surrounding integument (8)
Megalopta vs other selected genera
 Other selected genera - Ocelli variable, but not as large as is seen in Megalopta, usually several ocellar diameters away from the compound eyes - Females lacking any additional inner teeth (18)
 Megalopta - Ocelli greatly ENLARGED, the lateral ocelli being separated from the compound eyes usually by much less than the diameter of the ocelli - Females with a pair of distinct inner teeth, or at least bumps, along the inner side of the mandible, these teeth present IN ADDITION TO the subapical tooth, these teeth often entirely hidden when mandibles are closed (1)
Megommation vs other selected genera - This character is more reliable for females, although the propodeal pubescence character may help distinguish males
 Other selected genera - The basitibial plate of the hind leg is readily evident, extending over the tibia at least slightly - Males usually do not have dense, white plumose hairs surrounding the propodeal spiracle (5)
 Megommation - On the hind leg of the FEMALE, the BASITIBIAL PLATE GREATLY REDUCED such that it often appears absent, this applies to all species save for the one member of the subgenus Stilbochlora, which is restricted to South America and can be identified by its bright green coloration of the thorax and abdomen in both sexes as well as the presence of a dense tuft of plumose hairs surrounding the propodeal spiracle that is found in males of this group (1)
Melipona vs other selected genera
 Other genera - Wing length long, always extending beyond the edge of the abdomen, usually considerably so - Hamuli composed of usually 5-7 hooks, although rarely up to 10 - The margin of the stigma which meets the beginning of the marginal cell is slightly convex - In direct comparison, usually much more skinny looking (15)
 Melipona - Wing length short, only slightly extending beyond the end of the abdomen if at all - Hamuli composed of 9-14 hooks, rarely as few as 8 - The margin of the stigma which meets the beginning of the marginal cell is straight or weakly concave - In direct comparison, usually much more robust in appearance such that it more closely resembles a honey bee than other Meliponini (1)
Meliponini only - Hind leg, basitarsus, basal sericeous area
 Absent - The inner face of the basitarsus usually has its hairs spread about evenly throughout the surface, without a patch of very dense hairs at the base (14)
 Present - The inner face of the basitarsus is covered by a clear, dense patch of very short hairs at the base, this patch usually taking up a fourth to half of the length of the basitarsus (2)
Meliponini only - Rear leg, tibia, inner surface, the distribution of the extremely short and dense hairs, keirotrichia, found commonly in bees on the inner surface of the tibia, and are thought to be used for wing grooming - This character should work for both workers and males, although the states may be less obvious in the males
 Keirotrichial area covering the MAJORITY of the width of the inner surface of the hind tibia, often without any depressed zone, or if with a depressed zone then it is usually much LESS THAN half the width of the keirotrichial area (8)
 With a distinct, shiny and depressed area of the integument running alongside the keirotrichial area, this depressed zone equal to about half the width of the keirotricial area at the midpoint of the length of the tibia and about equal to or greater than its width near the apex (7)
Melissodes vs Martinapis
 Martinapis-Mandible of female strongly notched and therefore bilobed at apex but often worn so be careful and expanded apically so that preapical part is nearly as wide as base, female with last antennal segment about twice as long as broad, T7 of male without lateral teeth and middle tibial spurs weak being less than half as long as tibia, rare, Southwest (1)
 Melissodes-Mandible of female simple or scarcely notched with the widest preapical part less than three-fourths as wide as base, last antennal segment of female much less than twice as long as wide, T7 of male with teeth or strong angle on each side of the pygidial plate although sometimes hidden by dense hair or by T6, throughout US (1)
Melitoma vs Diadasia
 Diadasia-Proboscis in repose usually not reaching beyond front coxa and not reaching the base of the metasoma, western (1)
 Melitoma-Proboscis or tongue in repose reaching the base of the metasoma, extending to T1 or nearly so, throughout US but only one species Melitoma taurea in east (1)
Melitoma vs Protandrena
 Melitoma - The proboscis even when folded up under the head extends to the abdomen (1)
 Protandrena - The proboscis extends only a little ways onto the thorax even when extended (1)
Melitoma vs selected other genera
 Others - M-Cu of hind wing MORE THAN two- thirds as long as M and OVER 1.6 times as long as cu-v - Profile of head or vertex not continuously convex when seen from front, or, if generally convex, then FLAT or slightly concave between summit of eye and lateral ocellus (16)
 Melitoma - See the associated diagram and find vein sections M, M-Cu, and cu-v in the hind wing - M-Cu is LESS THAN two-thirds and often only half the length of M - M-Cu is LESS THAN 1.6 times as long as cu-v and often little longer than cu-v - Profile of the top or vertex of the head is CONVEX when seen looking at the face (1)
Melitta vs selected other genera with 3 submarginal cells
 Others, jugal lobe much more than 1/2 of vannal lobe. scopa of female - except parasitic genera which lack scopa - well developed on hind femur and sometimes trochanter (8)
 Melitta, jugal lobe of hind wing about 1/2 as long as vannal lobe, measured from wing base. scopa on female on hind tibia, not on those leg segments closer to the body (1)
Mesoxaea vs Protoxaea
 Mesoxaea - S8 of male deeply emarginate apically - T5 of female orT6 of male with conspicuous lateral tufts of long white hair (1)
 Protoxaea - S8 of male entire - T5 of female orT6 of male WITHOUT conspicuous lateral tufts of long white hair (1)
Mexalictus vs. Lasioglossum and Agapostemon
 Agapostemon-Body brightly metallic green at least in part and males with yellow markings, distributed throughout US (1)
 Lasioglossum-Distal veins in forewing WEAK and body often with basal hairs bands, female with inner hind tibial spur pectinate with a few large teeth, male with F2 of antenna longer than F1 and S7 with one apodeme on each side with a median apical projection, distributed throughout US (1)
 Mexalictus-Distal veins STRONG in forewing, T1-T4 WITHOUT basal hair bands female with inner hind tibial spur serrate, body weakly metallic and without yellow markings to distinguish from Agapostemon , male with F2 of antenna shorter than or as long as F1 and S7 with two apodemes on each side without an apical projection from Lasioglossum , Found in Southern AZ at high altitudes (1)
Micralictoides vs. Sphecodosoma
 Micralictoides - Dorsal surface of propodeum more than 2 times as long as metanotum - Clypeal margin of female truncate or scarcely rounded between lateral tubercles (1)
 Sphecodosoma - Dorsal surface of propodeum less than two times as long as metanotum - Clypeal margin of female strongly rounded between lateral tubercles - This group of species of Specodosoma were formerly known as Michenerula, rare (1)
Microsphecodes vs Nesosphecodes
 Microsphecodes - Often with yellow markings on the face or thorax - Pitting on scutum more dense on average, usually about equal to one pit diameter, although in some species the interspacing may be more sparse - In direct comparison, smaller on average, ranging about 3-7mm (1)
 Nesosphecodes - Never with yellow markings on the face or thorax - Pitting on scutum more sparse, with pit interspacing of at least 1-2 pit diameters and often up to 3-4 pit diameters - In direct comparison, larger on average, ranging 7.8-9.2mm according to Engel 2006 (1)
Monoeca and Paratetrapedia vs other selected genera
 Other genera - Mandible often, but not always, lacking a preapical tooth - Fore basitarsus without a thick brush of hairs posteriorly - Often with hair bands on the terga - MALE antennal length variable, ranging from about the same size as in Monoeca and Paratetrapedia to extremely long such that they surpass the thorax when held back over the head in repose - Scopa usually present, but if absent then not Monoeca or Paratetrapedia - Body form variable, most usually Eucerine like and some genera are also parasitic, although a few resemble Monoeca and Paratetrapedia in general body form (16)
 Monoeca and Paratetrapedia - Mandible always with at least one tooth present on the upper side or rarely two just behind the tip of the mandible - Fore basitarsus with a thick brush of hairs present running along the longitudinal axis of the basitarsus on its rear face, this used for oil collecting - Terga usually without any form of hair bands - MALE antennal length relatively normal, at most reaching back over the scutum when extending back over the head in repose - Scopa always present - Body form usually highly resembling members of Meliponini due to short abdomens and relatively long wings (2)
Nannotrigona and Scaptotrigona vs selected other genera
 Other genera - Vertex either without any carina or with only a weak carina only present along the very top of the head - The anteromedial area of the scutellum is unmodified (3)
 Nannotrigona and Scaptotrigona - Vertex with preoccipital area clearly carinate along the rim at the very back of the head, this slightly bent edge extending, at least, part way down either side of the head - In the center anterior portion of the scutellum, where it joins the scutum, there is a small, shiny triangular depression which points back posteriorly (2)
Neocorynura vs Pereirapis
 Neocorynura - Most males do not have light integument color along the apical rim of the clypeus, and the integument of the head is often, but not always, NOT metallic green - Thorax integumental color highly variable, sometimes a bright green similar to Pereirapis and sometimes much darker, blackish - The integument of the abdomen is highly variable in color, ranging from entirely metallic green to black - MALES with very SLENDER ABDOMENS, at least the first segment and very often the second as well appearing longer than wide or nearly so, giving them an appearance somewhat similar to some ichneumonid wasps - In direct comparison, usually several times LARGER than Pereirapis, although there is a great deal of size variation among the species of this group (1)
 Pereirapis - There is an apical light whitish-yellowish band on the apical rim of the clypeus in the males, in contrast to the otherwise metallic green head - Thorax always with bright, metallic green integumental coloration - Integumental coloration of abdomen ranging from orange to brown, usually with some metallic green highlights - MALES with abdomens that are not unusually constricted near the base - In direct comparison, MUCH SMALLER than most species of Neocorynura, body length averaging about 5-6mm (1)
Neolarra vs Perdita
 Neolarra, jugal lobe of hind wing less than one-fourth as long as vannal lobe. body partly covered with scale like hairs laying horizontal on surface. scopa absent. second submarginal sometimes missing (1)
 Perdita, jugal lobe of hind wing nearly three-fourths as long as vannal lobe or more. body without dense scale like hairs. scopa present on hind tibia of female (1)
Neopasites vs Townsendiella and Rhopalolemma
 Townsendiella and Rhopalolemma-Scape excluding bulb more than two times as long as broad, T6 of female with pygidial plate of which the apical margin is not concave, mandible simple (2)
 Neopasites-Scape excluding basal bulb less than two times as long as broad, T6 of female without pygidial plate, apical margin of which is broadly concave, mandible with preapical tooth (1)
Neopasites vs selected other genera
 Other genera - Scape longer, its length equal to about 2.5x its maximum width or more - T6 variable in form, but WITH a pygidial plate that is at least weakly defined and WITHOUT a deep medial concavity (2)
 Neopasites - Scape shorter, its length equal to twice its own maximum width at most, but usually shorter than this - T6 rim deeply emarginated and concave medially with no sign of a pygidial plate, the lateral sides of T6 coming to a point at each side (1)
Nesosphecodes vs Sphecodes
 Nesosphecodes - Mandibles simple and long, about equal in length or longer than the compound eye - Pitting on the scutum is sparse medially, the interspacing between pits often exceeding two pit diameters - The abdomen is always black - This genus is known only from the Caribbean (1)
 Sphecodes - Mandible can either be simple or often with a subapical tooth set back slightly from the tip, length variable but often shorter than the compound eye - Pitting on the scutum is usually dense, the interspacing between pits rarely if ever exceeding one pit diameter - The abdomen is often reddened either partially or wholly, although an all black abdomen is possible - This genus is found essentially worldwide (1)
Nomada and Osiris vs selected other genera
 Nomada and Osiris - Jugal lobe of hind wing small, one-sixth as long as vannal lobe or less. scopa absent (5)
 Others, jugal lobe of hind wing one-fourth to over three-fourths as long as vannal lobe. scopa present on hind legs of female (4)
Nomada vs Holcopasites and Townsendiella
 Nomada, tip of marginal cell resting on wing margin (3)
 Holcopasites and Townsendiella- tip of marginal cell curved away from wing margin (2)
Odyneropsis vs Epeolus and Triepeolus
 Epeolus and Triepeolus-Vein r arising near apex of stigma, margin of stigma in marginal cell not convex, greatest length of marginal cell usually distinctly less than the length of the three submarginal cells combined, no defined oval area on T5 of female, occurs in east and west (2)
 Odyneropsis-Vein r arising near middle of stigma or 3/5 of stigmal length from base, margin of stigma in marginal cell convex, greatest length of marginal cell subequal to greatest total length of the three submarginal cells combined, T5 of female with small basal longitudinal oval area depressed or surrounded by a carina or raised line, occurs only in west (1)
Odyneropsis vs Xeromelecta
 Odyneropsis - Forewings relatively evenly covered with minute hairs throughout - Abdomen with scattered dark hairs dorsally, although in some species there may be dense whitish hair patches present at the far sides of the tergites, if present then these patches are separated in the middle by well over half the latitudinal width of the terga - In terms of general body shape, this slender-bodied genus closely resembles paper wasps (1)
 Xeromelecta - Forewing largely HAIRLESS within the interior of the veined cells, although there may be some distinct hairs just below the radius and along its length before its intersection with the basal vein - Abdomen with light-colored hair patches found commonly interrupted narrowly at the middle of each tergite where they are present, although in some species this may seem less obvious due to these hairs being darker or more sparse - In direct comparison, this genus is much more robustly-bodied than Odyneropsis (1)
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 ADMIN ONLY - ALL (161)
 Apidae (79)
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 ADMIN ONLY - ALL (161)
 Apinae-Meliponini (16)
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 Halictinae-Augochlorini (10)
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 Apinae-Exomalopsini (3)
 Oxaeinae (3)
 Apinae-Centridini (2)
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 Apinae-Tapinotaspidini (2)
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 Apinae-Bombini (1)
 Apinae-Protepeolini (1)
 Hylaeinae (1)
 Xeromelissinae (1)
Oreopasites vs selected parasitic Anthidiini
 Other genera - OFTEN BUT NOT ALWAYS with extensive yellow or reddish markings present on the thorax - Tibia lacking distinctly thickened spikes, all hairs relatively similar throughout - Abdomen, usually only with limited red integumental markings (2)
 Oreopasites - A parasitic species ALMOST NEVER with ANY red on the head or thorax, although there is slight reddening in a small number of species - Tibia with thickened hairs which often appear more erect and spike-like throughout, these spikes obvious in contrast to the commonly appressed white hairs found throughout - Abdominal integument usually entirely red or nearly so (1)
Osmia vs selected other genera
 Others, parapsidal lines linear. body rarely metallic - although sometimes strongly so (10)
 Osmia, parapsidal lines simple pits or at most three times as long as broad. body usually metallic (1)
Oxaea vs other Oxaeinae
 Other Oxaeinae - Tergites dark BROWNISH OR BLACK, if with metallic reflections then they are only very slightly visible at certain angles - Maxillary palpus SIX-segmented - These genera are found in the southwestern United States as well as Central America (2)
 Oxaea - Tergites usually with strong METALLIC reflections at least along the apically impressed rim, these can be either green or bluish - Maxillary palpus ABSENT - This genus occurs no farther north than southern Mexico, most of the species occurring in South America (1)
Oxaeinae vs other Andrenidae
 Other Andrenidae - First antennal flagellomere shorter than scape, rarely about equal - Stigma present and obvious - Marginal cell of forewing less than five times as long as it is wide, with the width of the marginal cell about equal to that of the widest submarginal cell (11)
 Oxaeinae - First antennal flagellomere about as long as the scape - Stigma nearly absent, if apparent then very small - Marginal cell of forewing extremely long, clearly more than five times as long as it is wide, with the width of the marginal cell equal to only about half that of the widest submarginal cell (3)
Panurginus vs selected other genera
 Others - First recurrent vein intersects the second sub-marginal cell often well toward the tip of the wing from the location of the first transverse cubital - Pre - episternal groove present, sometimes very weak, running down and to the front from upper end, in some minute species this visible only at upper end and hair must be removed to see it -Sixth lowerside abdominal segment of male without thickened projection along rim, rim thin and concave or cleft (2)
 Panurginus - First recurrent vein meets the first transverse cubital or very nedarly so - Pre-episternal groove completely absent - Sixth underside abdominal segment of males with thickened median squared-off or slightly concave projection on rim (1)
Paranomada vs selected other genera
 Others-Integument largely with pits, thorax not unusually flattened (4)
 Paranomada-Integument almost entirely polished and without pits, thorax flattened with the greatest width nearly twice the height (1)
Paranthidium vs selected other genera
 Others - Front and middle tibia with small outer spine or tooth along the outer edge of the apical end on the anterior edge of the slightly projecting, semicircular flattened projection along that same edge, this projection is half hidden among the hairs and barely rises beyond the hairs if at all, additionally the spine is sometimes minute and visible only at certain angles, there is also no shining concave area behind the spine or projection, only hairs - Margin of tip of mandible variable (7)
 Paranthidium - Front and middle tibia without any outer spine at their apical ends, the outer edge of the apical end of the tibia has a broad projection with a round tip that slightly but clearly projects well beyond the surrounding hairs to be 2 or more times those hairs length on the surface of the tibia, behind this projection, is a hairless, shining and scoop-like area - Margin of tip of mandible straight and at an oblique angle to outer margin, about half as long as mandible (1)
Paratrigona vs other selected genera
 Other genera - Mandible of workers with at most 2 small teeth near the apex, sometimes absent - Scutellum thick and rounded from lateral view, not projecting over metanotum in the form of a thin shelf, or if shelf-like then it has a small, medial triangular depression along the border with the scutum (5)
 Paratrigona - Mandible of workers with 4 apical teeth present, although in some species they may be fused into two very large teeth - Scutellum projecting as thin shelf over the metanotum at least medially, WITHOUT a small triangular depression along the border with the scutum at the latitudinal midpoint of the shelf (1)
Partamona vs Plebeia and Scaura
 Plebeia and Scaura - Basal area of propodeum usually without hair - Hind tibia less broad, clearly less than three times as wide as hind femur - The concave area of the corbicula extends to, but does not surpass, the midpoint of the length of the tibia, limiting it to the apical half - Within the bare corbicular area of the hind tibia, the concave area starts at the apical end but does NOT extend basally beyond the halfway point of the tibia (2)
 Partamona - Basal area of propodeum, just posterior to metanotum, densely hairy - Hind tibia of worker greatly broadened, about three times as wide as hind femur - Within the bare corbicula area of the hind tibia the concave area extends from the apical end of the corbicula up and PAST the halfway point of the tibia (1)
Perdita vs selected other genera
 Others - Second submarginal cell not unusually small, usually with 4-sides, if triangular then apex always squared-off (31)
 Perdita - Often missing the second submarginal cell and only having 2 total as a result, but if the second submarginal cell is present then it is unusually small, triangular, and completely surrounded on two sides by first and third submarginals (1)
Plebeia vs Scaura
 Plebeia - Face with or without yellow markings - The hind basitarsi are not swollen, clearly thinner than the hind tibia (1)
 Scaura - Face lacking any yellow markings - The hind basitarsi are distinctly thickened, about equal to or greater than the breadth of the tibia (1)
Protandrena versus Anthemurgus
 Anthemurgus, clypeus in females black, with small yellow spot in males, overall head and thorax mainly black, propodeum without pits along lateral margin of triangle and dorsal surface of triangle finely reticulate (2)
 Protandrena, clypeus in females and males completely or nearly completely yellow, head and thorax with yellow areas, propodeum entirely densely pitted (1)
Protandrena vs Eulonchopria
 Eulonchopria-Body extremely coarsely pitted, certain terga with white to yellow integumental bands, preoccipital ridge formed as a strong lamella, uncommon, found in AZ (1)
 Protandrena-Body not especially coarsely pitted, terga without colored integumental bands, preoccipital ridge or area above eyes without lamella, found throughout US although somewhat rare in the east (1)
Protandrena vs selected other genera
 Others, lower margin of first submarginal cell shorter than to scarcely longer than third submarginal cell or nearly 1.3 times as long as third submarginal cell but if 1.3 times as long as the third submarginal then these having short robust bodies, proboscis long (16)
 Protandrena, lower margin of first submarginal cell at least 1.3 times as long as lower margin of the third submarginal cell, body elongate - like Halictus or Andrena, proboscis or tongue short (2)
Protodufourea vs. Conanthalictus and Sphecodosoma
 Conanthalictus and Sphecodosoma-Dorsal surface of propodeum longer than metanotum, about as long as scutellum (2)
 Protodufourea-Dorsal surface of propodeum about as long as metanotum rare CA and AZ (1)
Pseudaugochlora vs other selected genera
 Other genera - FEMALE with short, weakly serrate teeth on the inner hind tibial spur, or if these teeth are long then the inner corner of the clypeal suture where it borders the paraocular area forms an obtuse angle - Apical flagellomere of MALE normal - S4 of MALE with the hair present medially not being much more dense than on the rest of S4 (2)
 Pseudaugochlora - FEMALE with large teeth on the inner hind tibial spur that are much longer than wide and the inner corner of the clypeal suture where it borders the paraocular area forms a right or acute angle - Apical flagellomere of MALE HOOKED - S4 of MALE with strong patches of dense hairs near the middle (1)
Pseudaugochlora vs. other metallic green genera
 Others-Not as above and generally much more widely distributed and more common (6)
 Pseudaugochlora - Females with inner hind tibial spur with teeth longer than wide to differentiate from Augochlora and Augochlorella, however similar to Augochlora in the parocular lobe - Tegula rounded or normal to differentiate from Augochloropsis - Body not coarsely punctate and T2 and T3 not strongly depressed to differentiate from Temnosoma - Female with area above eyes rounded to produce a rounded ridge above the ocelli and malar area short - Male with S4 having a distinctive median patch of setae or hairs and F11 the last flagellomere hooked - Range extends from TX southward into much of South America (1)
Ptilocleptis vs Sphecodes
 Ptilocleptis - Mandible always simple, the single tip pointed and lacking a subapical tooth - Compound eyes much closer together at the bottom than at the top - Head usually only somewhat broader than long, if at all - Most species without a red abdomen, although one Mexican species does exhibit this trait - In direct comparison, body with less coarse pitting and sculpting throughout - This group is only known from Central and South America (1)
 Sphecodes - Mandible either simple or with a subpical tooth set slightly back from the tip - Compound eyes roughly the same distance apart at the bottom as at the top - Head usually distinctly broader than wide - Most often with at least a partially red abdomen, but entirely black in some males - In direct comparison, body with much more coarse pitting and sculpting throughout - This group is present virtually worldwide (1)
Ptiloglossa vs other selected genera
 Other selected genera - Outer hind tibial spur of MALE articulated normally at base similar to inner spur - Length of hind basitarsi of FEMALE more than twice as long as broad - Second hind tarsal segment longer than broad - Terga usually NONMETALLIC (3)
 Ptiloglossa - Outer hind tibial spur of MALE immovably fused to tibia - Hind basitarsi of FEMALE about twice as long as broad - Second hind tarsal segment broader than long - Tergites often weakly metallic, greenish or bluish (1)
Ptilothrix vs Centris
 Centris, second submarginal cell equal to or longer than first on lower margin. third submarginal smaller than others. stigma a small transverse suture (1)
 Ptilothrix, second submarginal cell much shorter than first and smaller than first and third. stigma distinct, longer than broad (1)
Rhopalolemma vs Townsendiella
 Rhopalolemma- Margin of second submarginal cell that borders the marginal cell nearly one half the length of the posterior margin of second submarginal - T5 of female with pseudopygidial area being approximately 3 times as wide as long - T6 of female with pygidial plate indicated laterally by a carina or raised line but apex with pygidial fimbria of short hairs and no sharply defined apex of the pygidial plate (1)
 Townsendiella - Margin of second submarginal cell that borders the marginal cell less than one third the posterior length of second submarginal - T5 of female without pseudopygidial area - T6 of female with well defined pygidial plate and no pygidial fimbria (1)
Rophitinae vs other selected subfamilies of Halictidae
 Other subfamilies - Antennal fossae normally found level to the midpoint of the compound eyes, or if lower then with more than one fossal diameter between the lower fossal margin and the upper margin of the clypeus - The FEMALE hind basitarsus has a small apical projection on its rim, upon which the penicillus, a small brush of hairs, is located, although some parasitic species do not have this character - The hind trochanter and femur of the FEMALE have well-developed scopal hairs, the longest of which are usually longer than the tibial scopal hairs, although in many parasitic taxa the hairs of all three segments are very reduced to absent - FEMALE labral apex variable, but very often with a strong projection of some sort found medially interrupting the outline of the rim of the labrum (24)
 Rophitinae - Antennal fossae usually arising BELOW the middle of the compound eyes AND the lower margin of the fossae usually within about one fossal diameter of the upper clypeal margin - The FEMALE hind basitarsus usually has a small projection on its apical end, but there is never a small brush of hairs present at its end - FEMALE with scopa reduced on the hind trochanter and femur, even the longest hairs here usually shorter than those of the tibia - The apex of the FEMALE labrum is relatively unmodified, truncate or rounded such that it DOES NOT come to any kind of point medially (6)
SECONDARY CHARACTER FOR EXPERIENCED USERS - Wing, marginal cell, tip shape AND location of the tip - NOTE, this is a key character, read BOTH sections COMPLETELY and CAREFULLY
 Rounded, squared-off, OR OR OR - pay attention this occurs a lot - if pointed then point 3 or more vein widths from margin of wing (75)
 Pointed, with point laying right on margin of wing OR OR OR if bent away from margin or squared off then tip less than 3 vein widths from margin (33)
Sphecodes vs selected other genera in Halictidae
 Others - Thorax integumental color variable, often metallic, although in some Halictus it may be black and dull - Females WITH scopa except for some parasitic Lasioglossum, all of which have a dull dark METALLIC green or blue sheen to their thorax and 2 WEAKENED veins in the submarginals, these veins are explained in detail elsewhere in the guide - Abdomen is never red but can be yellowish or orange in a few cases - Propodeal triangle variable but not USUALLY coarsely areolate - Thorax sculpturing, in general, weaker - Body frequently weakly or strongly metallic or bright green - Males either have yellow bordering the clypeal rim or the head is very narrow and the clypeus rim is produced or extends well beyond the imaginary line between the lower parts of the compound eyes - With or without apical hair bands (3)
 Sphecodes - Thorax dark black, never metallic - Females WITHOUT scopa on hind legs - Most, but not all, species have large amounts of RED on their abdomen - In most, but not all, species the propodeal triangle is sectioned into cells bordered by thick heavy lines, AREOLATE, the basal area usually with striations separating large pits - Much of the scutum and the rest of thorax commonly coarsely pitted and the mesepisturnum heavily sculptured, rugose to rugulose - Males most likely to be confused with black non-metallic species, particularly black Lasioglossums which often do not clearly have the weakened wing veins that females do, however, males Sphecodes do not have yellow on the clypeus, unlike most Halictus species and many of the Lasioglossum species, and USUALLY have extensive red on the abdomen which is rare in all the other genera, in the few red Lasioglossum species they have a scutum dulled by many microscopic lines and a relatively smooth mesepisternum - Without apical hair bands on the tergites, this separating them from male Halictus (1)
Sphecodosoma vs Xeralictus
 Sphecodosoma - Forewing with either 2 or 3 submarginal cells - Mid tibial spur with very minute teeth that are often hard to distinguish from one another and are very closely spaced - Smaller in direct comparison, size ranging from 3-6mm according to Bees of the World (1)
 Xeralictus - Forewing always with 3 submarginal cells - Mid tibial spur coarsely serrate, with each large tooth clearly independent and separated from the next - LARGER in direct comparison, size ranging from 11-12.5mm according to Bees of the World (1)
State or province where bee was collected
 ADMIN ONLY - ALL (160)
 Veracruz (125)
 Oaxaca (120)
 Puebla (120)
 Jalisco (119)
 Mexico - This is the state in Mexico, not the entirety of Mexico (119)
 Morelos (119)
 Michoacan (118)
 Guerrero (115)
 Colima (114)
 Tabasco (112)
 Zacatecas (112)
 Nayarit (111)
 Chiapas (109)
 Queretaro (109)
 Tlaxcala (109)
 Guanajuato (108)
 Hidalgo (107)
 Sonora (107)
 Aguascalientes (106)
 Durango (106)
 San Luis Potosi (106)
 Quintana Roo (105)
 Yucatan (105)
 Campeche (104)
 Sinaloa (104)
 Nuevo Leon (101)
 Chihuahua (100)
 Tamaulipas (100)
 Coahuila (97)
 AZ (96)
 NM (92)
 TX (86)
 CA (84)
 Baja California (79)
 Baja California Sur (76)
 NV (76)
 UT (72)
 CO (70)
 KS (64)
 FL (62)
 GA (62)
 MO (62)
 AL (61)
 IL (61)
 NC (61)
 MS (60)
 OK (60)
 NE (59)
 SC (59)
 IN (57)
 VA (56)
 DC (55)
 MD (55)
 TN (55)
 AR (54)
 DE (54)
 KY (54)
 LA (54)
 SD (54)
 WY (54)
 NJ (53)
 OH (53)
 IA (52)
 ID (52)
 OR (52)
 WV (52)
 PA (51)
 MT (50)
 ND (50)
 WI (50)
 NY (49)
 MI (46)
 WA (46)
 CT (43)
 MA (43)
 MN (43)
 British Columbia (40)
 RI (40)
 Ontario (39)
 VT (38)
 NH (37)
 ME (36)
 Alberta (35)
 Saskatchewan (33)
 Manitoba (32)
 Nova Scotia (32)
 Quebec (32)
 Cuba (31)
 New Brunswick (30)
 Dominican Republic (23)
 Jamaica (22)
 Prince Edward Island (21)
 Northwest Territories (17)
 AK (16)
 Bahamas (16)
 Haiti (16)
 Saint Vincent and Grenadines (16)
 Puerto Rico (15)
 Dominica (13)
 Yukon (13)
 Newfoundland and Labrador (12)
 Grenada (9)
 HI (7)
 Guadeloupe (6)
 Montserrat (6)
 Anguilla (4)
 Barbados (3)
 Saint Lucia (3)
 Nunavut (2)
 Saint Kitts and Nevis (2)
 Cayman Islands (1)
 Curacao (1)
Stelis vs selected other genera - Note that we are not talking about the large spur that occurs on the opposite side of the apical end of the tibia from the spines
 Others, middle leg tibia with one spine at end nearest tarsi. scopa of females present (13)
 Stelis, middle leg tibia with two spines at end nearest tarsi on outer side - for small specimens examine from top. scopa of female absent (1)
Temnosoma vs other bright metallic green genera
 Others - Body with small pits and a much smoother appearance - Males with T2 and T3 not strongly depressed basally - Many of these other genera are common and found throughout the US (9)
 Temnosoma - Body very coarsely pitted - Male with T2 and T3 strongly depressed basally - Scopa absent - Rare, mainly tropical to AZ (1)
Tetragonisca vs Trigona
 Tetragonisca - Mandible of worker with fewer than 4 teeth, the tip often appearing to be a single cutting edge - The basal sericeous area, which has very dense and short hairs, on the inner face of the hind basitarsus is often invaded by the longer hairs usually present only outside of this area in other related genera, although in some species of Tetragonisca there may be no long hairs here either - The basal sericeous area of the hind basitarsus is present only in females - Usually smaller in direct comparison, ranging from 4-5mm according to Bees of the World (1)
 Trigona - With 4-5 distinct teeth present on the mandible of the worker - The basal sericeous area of the hind basitarsus does not have any hairs in it which are as long as those found on the rest of the inner face of the basitarsus - The basal sericeous area of the hind basitarsus is present in both females and males - Usually larger in direct comparison, ranging from 5.5-11mm according to Bees of the World (1)
Tetrapedia vs other selected genera
 Other genera - Combination not as above (9)
 Tetrapedia - Fore basitarsus with a thick brush of dark hairs present, running longitudinally along the anterior portion of the outer face of the basitarsus - Female scopa AND male hind tibial hairs often most heavily branched arising from the apical fifth or so of the tibia, these more branched hairs often of a lighter color than is found on the rest of the tibia - Mid and hind tibial spur modified into a comb such that the teeth of the spur are very long at the base and become shorter as you travel to the apex of the spur, it should also be noted that there is only ONE HIND TIBIAL SPUR - General body form highly similar to most Meliponini due to its relatively short abdomen and long wings (1)
Thorax and or abdomen, markings on the surface - Note, this is NOT the hair color
 None, entire body black, brown, metallic or abdomen ALONE red. upperside of abdomen rarely with narrow cream - colored or dull yellowish markings along rims of segments (139)
 Bright yellow, white, or red - rarely, entirely red (46)
Thorax, axilla, shape
 Rear margin tame, without projection, in line with the rest of the scutellum (129)
 Axilla, end projecting out of the rear of the scutellum as a triangle, spine, or, rarely, rounded over (11)
Thorax, primary color - Note this is the base color, not the hair color, there can be various other markings in addition
 Other colors, this can include black, brown, red, yellow, and white colors (140)
 Blue, blue-green, or dark green, usually dulled by a rough surface or inscribed microscopic surface lines (23)
 Bright, shiny, race car, in-your-face green - at times with strong gold or blue overtones (22)
Thorax, propodeum, sculpting in the basal area found just posterior to the metanotum
 Surface either smooth or pitted non-linearly, without a band of strong pits and a carina found posterior to it, or with these characters ONLY weakly at the lateral sides (20)
 With a COMPLETE latitudinal band of strong, often squarish, pits and this band of pits is separated from the rest of the propodeum by a carina or raised line found posterior to it (7)
Thorax, scutellum, profile of top rear portion
 Less strongly convex, posterior third at an angle of 110 degrees or more to front part. scutum and scutellum not bituberculate. metanotum and base of propodeum often more nearly horizontal (69)
 Strongly convex in profile, posterior portion - at least behind spines and tubercles, when present - nearly at right angles to front portion. scutum and scutellum sometimes bilobed, bituberculate, or bispinose. metanotum and propodeum drop off steeply (31)
Thorax, upperside, hair length and general aspect
 Hairs normal looking, long or short, but upright not little tiny matted midget hairs (115)
 Hairs on these usually uncommon genera form lovely convoluted patterns of silver and black on the thorax and the abdomen, however, these hairs are so short as to be nearly microscopic so people often don t realize they are hairs mistaking these patterns for integumental patterns, however, under the microscope you will see that the hairs are prostrate, matted, and usually obscure the surface. (3)
Thygater vs other selected genera
 Other genera - Females with the gradulus of S2 either NOT FORMING A W or strongly produced as in the figure - Although several genera DO have long male antennae here as well they may be separated by the more well-defined pygidial plate, which is defined by ridges around its perimeter, and flagellomere 8 onward distinctly more slender than the preceding flagellomeres - Jugal lobe of hind wing variable, often less than half the length of the vannal lobe but some groups equal to or greater (18)
 Thygater - Female with the gradulus of S2 only weakly W-shaped with rounded bumps, sometimes this area nearly appears straight - Males with extremely long antennae, often reaching back to the tip of the abdomen, but flagellomere 8 onward are approximately the same thickness as the preceding segments - Jugal lobe of hindwing about half the length of vannal lobe or often more (1)
Tibial spur strength and middle tibial spur length of MALE selected genera
 Tibial spurs weak with middle tibial spur about equal to half or less than half as long as tibia measured from the base of spur to its anterior tibiofemoral articulation (4)
 Tibial spurs strong with middle tibial spur longer than half the length of the tibia (3)
Townsendiella vs Holcopasites
 Holcopasites - Labrum much longer than broad - Body coarsely pitted (1)
 Townsendiella - Labrum broader than long - Body finely pitted - Rare, southwestern (1)
Trachusa vs selected Anthidiini
 Other genera - Character combination not as above (3)
 Trachusa - Lateral ocelli closer to the compound eyes than the back of the head, except in the subgenus Metatrachusa - Hindwing with vein cu-v oblique, half as long as second abscissa of M Cu or longer, except in some Metatrachusa - The apical spine of the fore and mid tibia is blunted at its tip, usually extending only slightly past the rest of the tibial apex, extending anterobasally as a carina on the tibial surface - Lateral teeth not present on T6 of females or T5-6 of males - T7 of male not strongly bilobed, in direct comparison this segment is smaller and more hidden than in many other groups (1)
Trachusa vs selected other genera
 Others, length of the border between stigma and first submarginal cell longer than width of stigma. claws of female without teeth or with a tooth near base. clypeus and paraocular area not yellow or cream - colored (9)
 Trachusa, length of the border between stigma and first submarginal cell shorter than or about as long as width of stigma. claws of female cleft or with tooth near tip on inner side. clypeus and region between clypeus and eye of male usually yellow or cream - colored (1)
Triepeolus vs Epeolus
 Epeolus - T5 of FEMALE with apical patch of short silvery pubescence, this patch less than half as longitudinally long as broad - S6 of FEMALE with a pair of long, prominant, lateral, apical, projections whose ends flare out to form spoon shaped tips which are bordered with short stubby setae, note these projections are often retracted and may not be visible - MALE almost always with a distinct tooth slightly behind the mandible tip, but usually hidden if the mandibles are closed - Upper surface of MALE pygidial plate all in one plane (1)
 Triepeolus - T5 of FEMALE with a prominant, central, often beveled, patch of dark and silvery setae, this patch usually as longitudinally long as wide S6 of FEMALE with a pair of very long, prominant, lateral, apical, parallel-sided, narrow, rod-like projections the tips of which are bordered by elongated, hook-like setae, note S6 and its projections are often retracted and may not be visible - Mandible of MALE always simple, with no additional tooth along the upper margin - Sides of the pygidial plate usually, but not always, with a medial constriction, the face of the apical portion of the pygidial plate may also angle downwards following the constriction (1)
Trigonisca vs other selected genera
 Other genera - The angle formed within the marginal cell where the lower vein of the marginal cell joins the stigma is very acute, equal to 50 degrees or less - Mid-size to small bees, but rarely reaching the minute level of Trigonisca (15)
 Trigonisca - The angle formed within the marginal cell where the lower vein of the marginal cell joins the stigma is approximately at a right angle or only slightly acute, 70 degrees or greater - Often minute bees of 3mm or so (1)
Wing, basal vein of forewing
 Gently and UNIFORMLY arched or straight THROUGHOUT its length (135)
 Lower portion STRONGLY bent or arched (27)
Wing, jugal lobe of hind wing
 Present (158)
 Absent (5)
Wing, jugal to vannal lobe ratio
 Less, usually much less, than two-thirds as long (74)
 At least nearly three-fourths as long (31)
Wing, marginal cell, tip shape alone
 Pointed or squared off - truncate, can be minutely squared off (25)
 Rounded (13)
Wing, submarginal cell number
 3 (100)
 2 (55)
 1 (2)
Wing, surface
 Entire forewing with numerous minute hairs. wing surface beyond veins with no small bumps or, if so, with many of them ending in hairs or with hairs intermixed among them (71)
 Closed cells of forewing largely hairless. wing surface between wing tip and veins filled with small HAIRLESS bumps (7)
Xeroheriades vs other selected genera
 Other genera - Not with this combination of characters, more common and widespread (4)
 Xeroheriades - FEMALE S1 with a strong BILOBED PROCESS located just before the apex - FEMALE S6 with median and apical spikes which seem to form a triangular platform - T1 evenly convex, without any form of division between the anterior and posterior areas of the segment - The apical rim of T1-3 are somewhat concave near the middle - MALE with rim of S5 deeply notched medially, the margin of which usually has at least a few hairs with swollen tips that are wider at the tip than the base - This is a rare genus with one species that has only been found in the mountainous regions of the Mojave Desert of California (1)
Xeromelecta vs Melecta
 Melecta, inner rami of claws of middle and hind legs pointed more or less like outer rami, not wider than outer rami. top of first abdominal segment - T1 - with long hair like that of thorax (1)
 Xeromelecta, inner rami of claws of middle and hind legs broad, vertically expanded, lobelike although somewhat squared-off or pointed, not shaped like outer rami. T1 without or almost without long hair similar to thorax (1)
Xylocopa vs Protoxaea and Mesoxaea
 Protoxaea and Mesoxaea - Posterior basitarsis shorter than tibia, second submarginal cell at least half as broad on anterior as on posterior side, scopa well developed on hind trochanter and femur (2)
 Xylocopa - Posterior basitarsis longer than tibia, second submarginal cell greatly narrowed toward marginal cell, scopa largely on hind tibia (1)
Xylocopa vs selected other genera
 Others, marginal cell six times as long as broad or less, much more than half as wide as widest submarginal cell. stigma usually distinct (35)
 Xylocopa, marginal cell slender, seven times as long as broad and only a little over half as wide as widest submarginal cell. stigma absent (3)
Zacosmia vs Ptilothrix and Centris
 Ptilothrix and Centris-Scopa conspicuous on hind tibia of female, antenna of male not greatly thickened with the middle segments at most twice as wide as long, marginal cell much more than twice as long as stigma and extending beyond third submarginal cell (2)
 Zacosmia-Scopa absent, antenna of male greatly thickened with the middle segments several times as wide as long, marginal cell less than two times as long as stigma and not extending beyond the third submarginal cell (1)