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  3. Repeat steps 1 and 2, narrowing down the possibilities.
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Discover Life 520 kinds match:
Andrena ablegata  [popup]
Andrena accepta  [popup]
Andrena aculeata  [popup]
Andrena aerifera  [popup]
Andrena aeripes  [popup]
Andrena afimbriata  [popup]
Andrena agilis  [popup]
Andrena agoseridis  [popup]
Andrena alamonis  [popup]
Andrena albiculta  [popup]
Andrena albuginosa  [popup]
Andrena alceae  [popup]
Andrena algida  [popup]
Andrena aliciae  [popup]
Andrena aliciarum  [popup]
Andrena alleghaniensis  [popup]
Andrena amarilla  [popup]
Andrena amphibola  [popup]
Andrena anatolis  [popup]
Andrena andrenoides  [popup]
Andrena angelesia  [popup]
Andrena angustella  [popup]
Andrena angusticrus  [popup]
Andrena angustifovea  [popup]
Andrena angustitarsata  [popup]
Andrena anisochlora  [popup]
Andrena annectens  [popup]
Andrena anograe  [popup]
Andrena antonitonis  [popup]
Andrena apacheorum  [popup]
Andrena apasta  [popup]
Andrena arabis  [popup]
Andrena arctostaphylae  [popup]
Andrena ardis  [popup]
Andrena arenicola  [popup]
Andrena argemonis  [popup]
Andrena argentiscopa  [popup]
Andrena asteris  [popup]
Andrena asteroides  [popup]
Andrena astragali  [popup]
Andrena atlantica  [popup]
Andrena atypica  [popup]
Andrena auricoma  [popup]
Andrena aurihirta  [popup]
Andrena auripes  [popup]
Andrena autumnalis  [popup]
Andrena avulsa  [popup]
Andrena baeriae  [popup]
Andrena balsamorhizae  [popup]
Andrena banffensis  [popup]
Andrena banksi  [popup]
Andrena barbara  [popup]
Andrena barberi  [popup]
Andrena barbilabris  [popup]
Andrena beameri  [popup]
Andrena bendensis  [popup]
Andrena berberidis  [popup]
Andrena berkeleyi  [popup]
Andrena bernardina  [popup]
Andrena biareola  [popup]
Andrena bilimeki  [popup]
Andrena birtwelli  [popup]
Andrena bisalicis  [popup]
Andrena biscutellata  [popup]
Andrena blaisdelli  [popup]
Andrena blennospermatis  [popup]
Andrena bocensis  [popup]
Andrena boronensis  [popup]
Andrena braccata  [popup]
Andrena bradleyi  [popup]
Andrena brevicornis  [popup]
Andrena brevipalpis  [popup]
Andrena brooksi  [popup]
Andrena bruneri  [popup]
Andrena buccata  [popup]
Andrena bucculenta  [popup]
Andrena buckelli  [popup]
Andrena bullata  [popup]
Andrena caerulea  [popup]
Andrena caeruleonitens  [popup]
Andrena californiensis  [popup]
Andrena caliginosa  [popup]
Andrena calvata  [popup]
Andrena camissoniae  [popup]
Andrena canadensis  [popup]
Andrena candida  [popup]
Andrena candidiformis  [popup]
Andrena capricornis  [popup]
Andrena carlini  [popup]
Andrena carolina  [popup]
Andrena carolinensis  [popup]
Andrena casadae  [popup]
Andrena ceanothi  [popup]
Andrena ceanothifloris_ceanothifloris  [popup]
Andrena ceanothifloris_cretata  [popup]
Andrena cerasifolii  [popup]
Andrena cercocarpi  [popup]
Andrena cerebrata  [popup]
Andrena chalybaea  [popup]
Andrena chalybioides  [popup]
Andrena chaparralensis  [popup]
Andrena chapmanae  [popup]
Andrena cheyennorum  [popup]
Andrena chippewaensis  [popup]
Andrena chlorogaster  [popup]
Andrena chlorosoma  [popup]
Andrena chlorura  [popup]
Andrena chromotricha  [popup]
Andrena chylismiae  [popup]
Andrena citrinihirta  [popup]
Andrena clarkella  [popup]
Andrena cleodora_cleodora  [popup]
Andrena cleodora_melanodora  [popup]
Andrena coactipostica  [popup]
Andrena coconina  [popup]
Andrena colletina  [popup]
Andrena columbiana  [popup]
Andrena commoda  [popup]
Andrena compositarum  [popup]
Andrena concinnula  [popup]
Andrena confederata  [popup]
Andrena congrua  [popup]
Andrena coracina  [popup]
Andrena cornelli  [popup]
Andrena coruscata  [popup]
Andrena costillensis  [popup]
Andrena cragini  [popup]
Andrena crataegi  [popup]
Andrena crawfordi  [popup]
Andrena cressonii_cressonii  [popup]
Andrena cressonii_infasciata  [popup]
Andrena cressonii_kansensis  [popup]
Andrena crinita  [popup]
Andrena cristata  [popup]
Andrena critica  [popup]
Andrena cruciferarum  [popup]
Andrena crudeni  [popup]
Andrena cryptanthae  [popup]
Andrena cuneilabris  [popup]
Andrena cupreotincta  [popup]
Andrena cyanophila  [popup]
Andrena cyanosoma  [popup]
Andrena cybele  [popup]
Andrena cymatilis  [popup]
Andrena daeckei  [popup]
Andrena dallasiana  [popup]
Andrena dapsilis  [popup]
Andrena davidsoni  [popup]
Andrena declinis  [popup]
Andrena decolorata  [popup]
Andrena deppeana  [popup]
Andrena deserticola  [popup]
Andrena dimorpha  [popup]
Andrena discreta  [popup]
Andrena dissimulans  [popup]
Andrena dissona  [popup]
Andrena distans  [popup]
Andrena dolomellea  [popup]
Andrena dreisbachorum  [popup]
Andrena duboisi  [popup]
Andrena dunningi  [popup]
Andrena duplicata  [popup]
Andrena durangoensis  [popup]
Andrena edwardsi  [popup]
Andrena elongatula  [popup]
Andrena enocki  [popup]
Andrena eothina  [popup]
Andrena eremophyla  [popup]
Andrena erigeniae  [popup]
Andrena erythrogaster  [popup]
Andrena erythronii  [popup]
Andrena escondida  [popup]
Andrena evoluta  [popup]
Andrena excellens  [popup]
Andrena faceta  [popup]
Andrena fastuosa  [popup]
Andrena fenningeri  [popup]
Andrena ferrugineipes  [popup]
Andrena flaminea  [popup]
Andrena flandersi  [popup]
Andrena flexa  [popup]
Andrena flocculosa  [popup]
Andrena forbesii  [popup]
Andrena foxii  [popup]
Andrena fracta  [popup]
Andrena fragilis  [popup]
Andrena frigida  [popup]
Andrena fulgida  [popup]
Andrena fulminea  [popup]
Andrena fulminoides  [popup]
Andrena fulvicrista  [popup]
Andrena fulvipennis  [popup]
Andrena fumosa  [popup]
Andrena furva  [popup]
Andrena fuscicauda  [popup]
Andrena gardineri  [popup]
Andrena geranii  [popup]
Andrena gibberis  [popup]
Andrena gnaphalii  [popup]
Andrena gordoni  [popup]
Andrena grindeliae  [popup]
Andrena hallii  [popup]
Andrena hamulata  [popup]
Andrena hastulata  [popup]
Andrena haynesi  [popup]
Andrena helianthi  [popup]
Andrena helianthiformis  [popup]
Andrena hemileuca  [popup]
Andrena heraclei  [popup]
Andrena hermosa  [popup]
Andrena hicksi  [popup]
Andrena hilaris  [popup]
Andrena hippotes  [popup]
Andrena hirsutula  [popup]
Andrena hirticincta  [popup]
Andrena hondurasica  [popup]
Andrena hurdi  [popup]
Andrena hypoleuca  [popup]
Andrena ignota  [popup]
Andrena ilicis  [popup]
Andrena illini  [popup]
Andrena illinoiensis  [popup]
Andrena illustris  [popup]
Andrena imitatrix  [popup]
Andrena impolita  [popup]
Andrena impuncta  [popup]
Andrena inclinata  [popup]
Andrena inculta  [popup]
Andrena integra  [popup]
Andrena irrasus  [popup]
Andrena ishii  [popup]
Andrena isocomae  [popup]
Andrena jazleya  [popup]
Andrena jennei  [popup]
Andrena jessicae  [popup]
Andrena kaibabensis  [popup]
Andrena kalmiae  [popup]
Andrena knuthiana  [popup]
Andrena kraussi  [popup]
Andrena krigiana  [popup]
Andrena kristina  [popup]
Andrena labergei  [popup]
Andrena lamelliterga  [popup]
Andrena laminibucca  [popup]
Andrena lanhami  [popup]
Andrena latifrons  [popup]
Andrena latinensis  [popup]
Andrena lativentris  [popup]
Andrena lauracea  [popup]
Andrena lauta  [popup]
Andrena lawrencei  [popup]
Andrena layiae  [popup]
Andrena lepidii  [popup]
Andrena leucomystax  [popup]
Andrena levigata  [popup]
Andrena levipes  [popup]
Andrena lewisorum  [popup]
Andrena lillooetensis  [popup]
Andrena limatula  [popup]
Andrena linsleyana  [popup]
Andrena linsleyi  [popup]
Andrena livida  [popup]
Andrena lomatii  [popup]
Andrena longifovea  [popup]
Andrena lupinorum  [popup]
Andrena luteihirta  [popup]
Andrena mackieae  [popup]
Andrena macoupinensis  [popup]
Andrena macra  [popup]
Andrena macrocephala  [popup]
Andrena macswaini  [popup]
Andrena malacothricidis  [popup]
Andrena mandibularis  [popup]
Andrena manifesta  [popup]
Andrena mariae  [popup]
Andrena mariposorum  [popup]
Andrena medionitens  [popup]
Andrena melanochroa  [popup]
Andrena mellea  [popup]
Andrena melliventris  [popup]
Andrena mendica  [popup]
Andrena mentzeliae  [popup]
Andrena merriami  [popup]
Andrena mesillae  [popup]
Andrena mesoleuca  [popup]
Andrena mexicana  [popup]
Andrena micheneri  [popup]
Andrena micheneriana  [popup]
Andrena micheneriella  [popup]
Andrena microchlora  [popup]
Andrena milwaukeensis  [popup]
Andrena mimbresensis  [popup]
Andrena miniata  [popup]
Andrena miranda  [popup]
Andrena misella  [popup]
Andrena miserabilis  [popup]
Andrena modesta  [popup]
Andrena mohavensis  [popup]
Andrena mojavensis  [popup]
Andrena monilicornis  [popup]
Andrena monoensis  [popup]
Andrena monogonoparia  [popup]
Andrena monticola  [popup]
Andrena moquiorum  [popup]
Andrena morrisonella  [popup]
Andrena murietae  [popup]
Andrena n.sp. 12  [popup]
Andrena n.sp. 7  [popup]
Andrena nasonii  [popup]
Andrena neffi  [popup]
Andrena nemophilae  [popup]
Andrena neomexicana  [popup]
Andrena neonana  [popup]
Andrena nevadae  [popup]
Andrena nevadensis  [popup]
Andrena nida  [popup]
Andrena nigerrima  [popup]
Andrena nigra  [popup]
Andrena nigrae  [popup]
Andrena nigricula  [popup]
Andrena nigrihirta  [popup]
Andrena nigripes  [popup]
Andrena nigrocaerulea  [popup]
Andrena nigroclypeata  [popup]
Andrena nivalis  [popup]
Andrena nothocalaidis  [popup]
Andrena nothoscordi  [popup]
Andrena nubecula  [popup]
Andrena nuda  [popup]
Andrena obscuripennis  [popup]
Andrena obscuripostica  [popup]
Andrena oenotherae  [popup]
Andrena ofella  [popup]
Andrena olivacea  [popup]
Andrena omninigra  [popup]
Andrena oniscicolor  [popup]
Andrena optanda  [popup]
Andrena orizabibia  [popup]
Andrena orthocarpi  [popup]
Andrena osmioides  [popup]
Andrena pachucensis  [popup]
Andrena padoucorum  [popup]
Andrena pallidifovea  [popup]
Andrena pallidiscopa  [popup]
Andrena palpalis  [popup]
Andrena papagorum  [popup]
Andrena parachalybea  [popup]
Andrena parilis  [popup]
Andrena parnassiae  [popup]
Andrena patagiata  [popup]
Andrena peckhami  [popup]
Andrena pecosana  [popup]
Andrena pectidis  [popup]
Andrena pectilis  [popup]
Andrena penemisella  [popup]
Andrena pensilis  [popup]
Andrena penutiani  [popup]
Andrena perarmata  [popup]
Andrena perimelas  [popup]
Andrena perplexa  [popup]
Andrena perpunctata  [popup]
Andrena persimulata  [popup]
Andrena personata  [popup]
Andrena pertristis_carliniformis  [popup]
Andrena pertristis_pertristis  [popup]
Andrena phaceliae  [popup]
Andrena phenax  [popup]
Andrena piperi  [popup]
Andrena placata  [popup]
Andrena plana  [popup]
Andrena platyparia  [popup]
Andrena platyrhina  [popup]
Andrena plebeia  [popup]
Andrena plumiscopa  [popup]
Andrena polemonii  [popup]
Andrena porterae  [popup]
Andrena prima  [popup]
Andrena primulifrons  [popup]
Andrena principalis  [popup]
Andrena prolixa  [popup]
Andrena pruni  [popup]
Andrena prunifloris  [popup]
Andrena prunorum_prunorum  [popup]
Andrena prunorum_sinaloa  [popup]
Andrena pulverea  [popup]
Andrena limnanthis
Andrena pulverulenta  [popup]
Andrena puthua  [popup]
Andrena quadrilimbata  [popup]
Andrena quercina  [popup]
Andrena quintiliformis  [popup]
Andrena quintilis  [popup]
Andrena ramaleyi  [popup]
Andrena rava  [popup]
Andrena raveni  [popup]
Andrena reflexa  [popup]
Andrena regularis  [popup]
Andrena rehni  [popup]
Andrena repanda  [popup]
Andrena revelstokensis  [popup]
Andrena ribblei  [popup]
Andrena robertsonii  [popup]
Andrena robinsoni  [popup]
Andrena rodilla  [popup]
Andrena rozeni  [popup]
Andrena rubens  [popup]
Andrena rubi  [popup]
Andrena rubrotincta  [popup]
Andrena rudbeckiae  [popup]
Andrena rufosignata  [popup]
Andrena rugosa  [popup]
Andrena runcinatae  [popup]
Andrena robervalensis Mitchell
Andrena saccata  [popup]
Andrena sagittagalea  [popup]
Andrena salicifloris  [popup]
Andrena salictaria  [popup]
Andrena sancta  [popup]
Andrena santaclarae  [popup]
Andrena sayi  [popup]
Andrena schuhi  [popup]
Andrena scotoptera  [popup]
Andrena sculleni  [popup]
Andrena scurra  [popup]
Andrena scutellinitens  [popup]
Andrena segregans  [popup]
Andrena semifulva  [popup]
Andrena semipunctata  [popup]
Andrena senticulosa  [popup]
Andrena shoshoni  [popup]
Andrena siccata  [popup]
Andrena sigmundi  [popup]
Andrena simplex  [popup]
Andrena simulata  [popup]
Andrena singularis  [popup]
Andrena sitiliae  [popup]
Andrena sladeni  [popup]
Andrena sodalis  [popup]
Andrena sola  [popup]
Andrena solivaga  [popup]
Andrena sonorensis  [popup]
Andrena specularia  [popup]
Andrena sperryi  [popup]
Andrena sphaeralceae  [popup]
Andrena spiraeana  [popup]
Andrena stagei  [popup]
Andrena stictigastra  [popup]
Andrena stipator  [popup]
Andrena striatifrons  [popup]
Andrena suavis  [popup]
Andrena subapasta  [popup]
Andrena subaustralis  [popup]
Andrena subchalybea  [popup]
Andrena subdepressa  [popup]
Andrena sublayiae  [popup]
Andrena submaura  [popup]
Andrena submoesta  [popup]
Andrena subnigripes  [popup]
Andrena subrubicunda  [popup]
Andrena subtilis  [popup]
Andrena subtrita  [popup]
Andrena sulcata  [popup]
Andrena surda  [popup]
Andrena taeniata  [popup]
Andrena tegularis  [popup]
Andrena tetonorum  [popup]
Andrena texana  [popup]
Andrena thaspii  [popup]
Andrena tildeni  [popup]
Andrena timberlakei  [popup]
Andrena toluca  [popup]
Andrena tonkaworum  [popup]
Andrena topazana  [popup]
Andrena toralis  [popup]
Andrena torulosa  [popup]
Andrena transnigra  [popup]
Andrena trapezoidea  [popup]
Andrena trapezoidina  [popup]
Andrena trevoris  [popup]
Andrena tridens  [popup]
Andrena trimaculata  [popup]
Andrena triquestra  [popup]
Andrena trivialis  [popup]
Andrena trizonata  [popup]
Andrena unicostata  [popup]
Andrena utahensis  [popup]
Andrena uvulariae  [popup]
Andrena uyacensis  [popup]
Andrena vanduzeei  [popup]
Andrena vandykei  [popup]
Andrena venata  [popup]
Andrena verbesinae  [popup]
Andrena verecunda  [popup]
Andrena vespertina  [popup]
Andrena vestali  [popup]
Andrena vicina  [popup]
Andrena vicinoides  [popup]
Andrena vidalesi_panamensis  [popup]
Andrena vidalesi_vidalesi  [popup]
Andrena vierecki  [popup]
Andrena vinnula  [popup]
Andrena violae  [popup]
Andrena virginiana  [popup]
Andrena viridissima  [popup]
Andrena vogleri  [popup]
Andrena vulpicolor  [popup]
Andrena vulpoides  [popup]
Andrena w-scripta  [popup]
Andrena waldmerei  [popup]
Andrena walleyi  [popup]
Andrena washingtoni  [popup]
Andrena wellesleyana  [popup]
Andrena wheeleri  [popup]
Andrena wilkella  [popup]
Andrena wilmattae  [popup]
Andrena winnemuccana  [popup]
Andrena xanthigera  [popup]
Andrena zionensis  [popup]
Andrena ziziae  [popup]
Andrena ziziaeformis  [popup]
Female  [popup]
Stylopized specimen  [popup]


REMAINING (number with state)
A. uvulariae vs. A. ziziaeformis
 A. uvulariae - Scutum, a patch near the central area towards the scutellum, shiny and glossy, without any finely engraved lines to dull the surface, sides of scutum can be entirely dulled by such lines - The interior of the propodeal triangle is almost exactly the same texture as that outside the triangle - The mid tibial spur is bent at the tip by 45 degrees - In direct comparison a rare species and the base of the mandible more massive (1)
 A. ziziaeformis - Scutum entirely dull from a dense mesh of finely engraved lines - The interior of the propodeal triangle slightly but clearly noticably more bumpy than the integument just outside of the propodeal triangle - The mid tibial spur is straight or nearly so at the tip - Relatively uncommon species (1)
Body length, in mm
 Zz Do not show this character again (520)
 9 (412)
 8 (409)
 10 (383)
 7 (341)
 11 (292)
 6 (222)
 12 (191)
 13 (112)
 5 (97)
 14 (58)
 4 (30)
 15 (17)
 3 (5)
 16 (4)
 17 (1)
Flight Season - Month
 5. May (375)
 4. April (356)
 6. June (326)
 3. March (305)
 7. July (299)
 8. August (226)
 2. February (176)
 9. September (152)
 10. October (99)
 11. November (54)
 1. January (50)
 12. December (18)
Head, antennae, length of first flagellomere
 3. Longer than second flagellomere but not as long as second plus third (327)
 4. As long as or longer than second plus third flagellomeres together (148)
 2. About as long as second flagellomere (127)
 1. Shorter than second flagellomere (87)
Head, cheek shape in profile
 1. Normal, rear margin smoothly rounded from bottom to top (388)
 2. With distinct angle of 90 degrees or more along lower rear margin breaking the curve from top to bottom (117)
 3. Posteroventral angle acute, forming a blunt process opposite middle of eye (27)
 UNCOMMON: With a large, blunt projection on lower cheek area just behind mandibles (4)
 UNCOMMON: With an elongate, narrow projection on lower cheek area just behind mandibles AND with a posteroventral angle along rear margin (1)
Head, cheek, carina or ridge along rear edge of cheek
 Absent (235)
 Present, only in lower half of genal area or near posteroventral angle, often weak (16)
 Present, distinct, spanning almost entire rear margin of gena (9)
 Present but weak and only in upper half of genal area (6)
Head, cheek, maximum width relative to eye
 3. From 1 to 1.25 times as broad as eye (114)
 4. From 1.25 to 1.5 times as broad as eye (106)
 5. From 1.5 to 1.75 times as broad as eye (105)
 1. As broad as eye or slightly narrower (96)
 6. From 1.75 to 2 times as broad as eye (59)
 7. About twice as broad as eye (27)
 8. More than twice as broad as eye (12)
Head, cheek, position of widest point in profile
 3. Above middle of eye (184)
 2. Near middle of eye (81)
 1. Below middle of eye (18)
Head, clypeus and parocular areas, color of integument
 Both entirely dark (315)
 Clypeus with at least some yellow, parocular areas dark (124)
 Both with at least some yellow (92)
 Clypeus with at least some metallic reflections (37)
 UNCOMMON: Clypeus dark, parocular areas with at least some yellow (4)
Head, clypeus, free apical margin
 Not distinctly upturned, width varies but usually at least half of total clypeal width (210)
 Distinctly upturned, width usually less than half of total clypeal width (12)
Head, clypeus, hairs
 Only dense laterally and sometimes apicomedially, at least partially obscuring surface (127)
 Dense throughout, at least partially obscuring surface (81)
 Sparse throughout, not obscuring surface (35)
Head, clypeus, impunctate midline
 Absent (170)
 Present (45)
Head, clypeus, punctures in central area, except impunctate midline when present
 Separated by 1 puncture width (83)
 Separated by 1-3 puncture widths (72)
 Dense, separated by less than 1 puncture width (69)
 Separated by 3 or more puncture widths (37)
 Absent or obscure (29)
Head, clypeus, surface texture between punctures
 SHINY in center and DULLED at least along dorsal and lateral margins (120)
 DULLED throughout (71)
 SHINY throughout (54)
Head, face, hair color
 All pale (198)
 Mostly pale, with dark hairs along vertex and/or inner margins of eyes (16)
 Mostly dark, sometimes with a few pale hairs along vertex (6)
Head, facial quadrangle
 2. QUADRATE, about as broad as long (204)
 1. BROADER than long (191)
 3. LONGER than broad (166)
Head, labral process, margin
 2. Weakly emarginate (164)
 3. Emarginate but not bidentate (135)
 4. Bidentate (116)
 1. Entire, edge continuous from side to side (114)
 5. Pointed (3)
 6. UNCOMMON: With a distinct medial horn almost as long as the process itself (3)
 7. UNCOMMON: process weak and margin somewhat sinuous (2)
Head, malar area, minimum length
 2. Short, between one and two times the eye rim (112)
 1. Extremely short, no wider than rim of compound eye (97)
 3. Moderate, more than twice the eye rim but not 1/5 as long as broad (52)
 4. Long, 1/5 to 1/3 as long as broad (21)
 5. Extremely long, more than 1/3 as long as broad (5)
Head, mandible, formation at base
 Normal, bottom margin of mandible narrowing smoothly to base (233)
 With a basal angle or weak tooth not projecting below level of mandible articulation (32)
 With a distinct basal tooth projecting below level of mandible articulation (22)
Head, mandible, length when mandibles closed
 Short, female-like, only one tip visible when mandibles closed (146)
 Moderate, somewhat decussate but not forming a clear X, tips exceed clypeus midline by 1/4 to 1/3 mandible length (94)
 Long, distinctly decussate, forming an clear X, tips exceed clypeus midline by more than 1/3 mandible length (63)
Head, maxillary palpus length
 4. Exceeds galea by two palpal segments or slightly less (190)
 5. Exceeds galea by three palpal segments or slightly less (134)
 1. Shorter than galea (62)
 3. Exceeds galea by one palpal segment or slightly less (50)
 2. Equal in length to galea (30)
Head, vertex height
 2. About 1 ocellar diameter (214)
 3. More than 1 to 1.5 ocellar diameters (204)
 1. Less than 1 ocellar diameter (147)
 4. More than 1.5 to 2 ocellar diameters (103)
 5. Two or more ocellar diameters (42)
Initial inspection
 1. Normal MALE (517)
 2. Normal FEMALE (1)
 3. UNCOMMON: Stylopized (1)
Legs, hind legs, rear tibial spurs
 Normal, similar to fore tibial spur, nearly straight and not distinctly broadened near base (310)
 Slightly but obviously bent and sometimes slightly twisted about one-third from apex (8)
 Strongly bent at least in outer half AND broadened and flattened near base (4)
 UNCOMMON: Distinctly curved at least in outer half (3)
 UNCOMMON: With apex sharply hooked (1)
Locality where specimen was collected in Canada
 Zz Do not show this character again (517)
 British Columbia (106)
 Ontario (87)
 Alberta (72)
 Quebec (72)
 Saskatchewan (56)
 Manitoba (52)
 New Brunswick, Nova Scotia, or Prince Edward Island (48)
 Northwest Territories or Nunavut (16)
 Yukon (14)
 Newfoundland or Labrador (10)
Locality where specimen was collected in Mexico
 Zz Do not show this character again (520)
 Baja California (107)
 Chihuahua (77)
 Sonora (77)
 Coahuila (48)
 Hidalgo (38)
 Distrito Federal (37)
 Mexico (37)
 Morelos (36)
 Puebla (35)
 Tlaxcala (34)
 Guanajuato (33)
 Queretaro (33)
 Michoacan (31)
 Nuevo Leon (31)
 Zacatecas (30)
 Durango (28)
 Tamaulipas (28)
 Jalisco (26)
 Guerrero (25)
 San Luis Potosi (23)
 Veracruz (23)
 Aguascalientes (22)
 Oaxaca (19)
 Nayarit (11)
 Sinaloa (11)
 Chiapas (5)
 Baja California Sur (4)
 Colima (1)
Locality where specimen was collected in USA
 Zz Do not show this character again (520)
 CA (262)
 NV (167)
 CO (154)
 AZ (149)
 NM (147)
 WY (147)
 UT (142)
 OR (140)
 ID (129)
 WA (124)
 NE (118)
 TX (118)
 MT (115)
 PA (108)
 IL (107)
 NJ (107)
 IN (103)
 SD (103)
 WV (103)
 MD (101)
 DE (100)
 OH (100)
 VA (100)
 DC (99)
 NY (99)
 MO (97)
 NC (97)
 KY (96)
 TN (93)
 KS (92)
 MI (92)
 WI (91)
 CT (90)
 MA (90)
 RI (90)
 SC (90)
 GA (89)
 IA (87)
 MN (82)
 NH (76)
 VT (76)
 ND (74)
 OK (74)
 ME (73)
 AR (59)
 AL (53)
 MS (46)
 LA (37)
 FL (27)
 AK (15)
Locality where specimen was collected south of Mexico
 Zz Do not show this character again (517)
 Nicaragua (7)
 El Salvador (5)
 Guatemala (5)
 Honduras (5)
 Costa Rica (3)
 Panama (3)
Metasoma, T7, pygidial area - be careful as T7 can be hard to see
 2. ABSENT, WITH a bare midline - midline narrow with neither its apex nor sides delimited by a raised margin (106)
 1. ABSENT, NO bare midline - area evenly covered with hair (92)
 3. PRESENT, APEX only delimited by a raised margin (49)
 4. PRESENT, APEX and SIDES delimited by a raised margin (13)
Metasoma, color of integument
 1. All DARK, black to reddish-brown, without distinct red or orange coloration or metallic reflections (363)
 3. With FAINT metallic reflections visible with a microscope, otherwise dark (57)
 4. With distinct METALLIC reflections visible to the naked eye, bluish or greenish (43)
 2. RED or orange, at least in part, without metallic reflections (18)
Metasoma, sternum 3, apical fringe of hairs
 Absent or indistinct, apical hairs not denser than elsewhere (112)
 Distinct, straight (96)
 Distinct, curled (28)
Metasoma, sternum 6, apex shape in lateral view
 Flat, not reflexed apically although sides may be slightly upturned (202)
 Reflexed apically across entire margin (76)
 Center only of apex reflexed (16)
 With lateral edges distinctly reflexed to form teeth, center may be reflexed or flat (5)
Metasoma, sternum 6, apical margin viewed from bottom
 Not emarginate, entire or sinuous (110)
 Gently emarginate, with a broad, rounded concave margin (50)
 Distinctly emarginate, V- or U-shaped (29)
 UNCOMMON: Rounded outward, convex (3)
Metasoma, sternum 6, surface hair
 Various, but not as above (198)
 Dense across entire margin, forming a band that contrasts with sparse basal hairs (39)
 Dense tuft only in the center of the apex (12)
Metasoma, sternum 8, apical margin
 4. Entire (264)
 3. Weakly emarginate (210)
 2. Emarginate (79)
 5. Scalloped (19)
 1. Distinctly notched, bidentate (15)
Metasoma, tergum 2, pale apical hair bands
 4. Absent, hair on apical margin not denser than elsewhere (251)
 3. Broadly interrupted, more than half of apical margin bare (226)
 2. Narrowly interrupted medially, no more than half of apical margin bare (178)
 1. Complete, not interrupted medially (86)
Metasoma, tergum 2, punctures - Primarily in the region from the base of the segment to the edge of the slightly depressed portion of the rim
 Absent or indistinct and difficult to see even at high magnification (87)
 Dense, separated by less than 1 puncture width (52)
 Separated by 1-3 puncture widths (52)
 Separated by 3-6 puncture widths (29)
 Sparse, separated by more than 6 puncture widths (13)
Metasoma, tergum 2, surface texture in middle of tergum
 GRANULAR or with fine lines, usually dull but may still be somewhat shiny (263)
 SMOOTH and SHINY (157)
Region where specimen was collected
 Zz Do not show this character again (520)
 1. United States (477)
 3. Mexico (218)
 2. Canada (164)
 4. South of Mexico (7)
Some geographic areas of this guide is UNDER CONSTRUCTION - See the options below
 4. Click here to keep all species in the key - note that many western species haven t been completely scored so the guide is unlikely to resolve many species (518)
 3. Click here to include all species except those rare and potentially invalid species we have not seen - note that many western species have not been completely scored so the guide may not resolve them (447)
 2. Click here to include all eastern species and exclude all western species (129)
 1. Click here to key bees from east of the Mississippi - excludes western species and those rare and potentially invalid species we have not seen (120)
Subgenus - for Andrena experts only
 Zz Do not show this character again (518)
 Callandrena (91)
 Andrena s.str. (45)
 ZUnassigned (32)
 Melandrena (30)
 Cnemidandrena (28)
 Diandrena (25)
 Euandrena (25)
 Trachandrena (25)
 Scaphandrena (24)
 Onagrandrena (22)
 Micrandrena (21)
 Scrapteropsis (19)
 Thysandrena (18)
 Tylandrena (15)
 Leucandrena (12)
 Simandrena (11)
 Derandrena (10)
 Parandrena (10)
 Hesperandrena (9)
 Gonandrena (7)
 Holandrena (7)
 Plastandrena (7)
 Belandrena (6)
 Dactylandrena (4)
 Rhacandrena (4)
 Archiandrena (3)
 Augandrena (3)
 Dasyandrena (3)
 Nemandrena (3)
 Oligandrena (3)
 Ptilandrena (3)
 Anchandrena (2)
 Aporandrena (2)
 Conandrena (2)
 Genyandrena (2)
 Notandrena (2)
 Psammandrena (2)
 Rhaphandrena (2)
 Scoliandrena (2)
 Celetandrena (1)
 Charitandrena (1)
 Chaulandrena (1)
 Cremnandrena (1)
 Erandrena (1)
 Geissandrena (1)
 Iomelissa (1)
 Larandrena (1)
 Opandrena (1)
 Oxyandrena (1)
 Pelicandrena (1)
 Taeniandrena (1)
 Xiphandrena (1)
Thorax, pronotum humeral angle
 ABSENT, rear edge of pronotum smoothly rounded (102)
 Present, but WEAK, with rounded angle but not distinct corners (83)
 Present, distinctly squared off forming CORNERS (69)
Thorax, pronotum, ridge extending down from humeral angle
 1. Absent, no trace of ridge present (145)
 3. Distinct, ridge angular and extending at least half height of pronotum (43)
 2. Weak but present, apex of ridge rounded, not distinctly angled (31)
 4. Distinct AND ridge deeply impressed by a diagonal suture (6)
 5. Weak but present AND ridge deeply impressed by a diagonal suture (3)
Thorax, propodeal triangle, form of sculpturing
 1. Finely sculptured throughout, tessellate except sometimes rugulate in basal fourth (79)
 3. With coarse, irregular rugulae in half or more of triangle (55)
 2. With fine, irregular rugulae in half or more of triangle (46)
 UNCOMMON: With longitudinal rugulae in basal half, tessellate or smooth at apex (44)
 4. Areolate (26)
 UNCOMMON: With transverse striae in basal half, tessellate or smooth at apex (7)
 UNCOMMON: With fine, irregular rugulae in basal half or less AND smooth and shiny elsewhere (1)
Thorax, propodeal triangle, percentage of LENGTH, measured from base, coarsely sculptured
 5 - 50 percent (103)
 50 - 80 percent (63)
 100 percent - triangle completely filled (48)
 0 percent - triangle uniformly smooth (44)
Thorax, propodeal triangle, transverse ridge separating dorsal and posterior surfaces
 Absent (309)
 Present (42)
Thorax, propodeum, form
 Normal, with distinct dorsal and posterior surfaces (394)
 Declivous, sloping gradually from base to apex, without distinct dorsal surface (12)
Thorax, propodeum, texture on posterior surface outside triangle
 Dulled by tessellation or shagreening (95)
 Coarsely and irregularly roughened (74)
 Areolate (22)
 Tessellation extremely fine, surface somewhat shiny (10)
Thorax, scutum, form of hair
 Long throughout, more than half as long as hairs on mesepisternum (136)
 Short medially, half as long as hairs on mesepisternum, but not mat-like (18)
 Absent or extremely sparse medially, hairs around edges of scutum long, more than half as long as hairs on mesepisternum (12)
Thorax, scutum, punctures between parapsidal lines, except midline area
 Separated by 1-3 puncture widths (114)
 Absent or obscure (71)
 Separated by 1 puncture width or less (65)
 Separated by 3 or more puncture widths (21)
Thorax, scutum, texture
 Dulled throughout, tessellate (130)
 Mostly dull, but somewhat shiny posteromedially where tessellation is weaker (43)
 Smooth and shiny medially, tessellation extremely weak except around edges (30)
Thorax, tegulae, surface texture in posterior half
 Impunctate (516)
 Punctate (3)
Wing, forewing, vein m-cu meets second submarginal cell
 1. Before middle of cell (159)
 2. At middle of cell (126)
 3. Slightly beyond middle (120)
 4. About two-thirds of the way from base of cell (93)
 5. About three-fourths of the way from base of cell (60)
 6. Near apex of cell (29)
Wings, forewing, number of submarginal cells
 3 (472)
 2 (140)
Wings, forewing, stigma size
 About as broad as prestigma (109)
 Broader than prestigma, but vein r longer than 4 vein widths (105)
 Distinctly broader than prestigma, AND vein r shorter than 4 vein widths (38)
Wings, membrane color
 Pale tan throughout (33)
 Pale, slightly darker at apex beyond veination (15)
 Dark throughout (4)
 Darker at apex beyond veination AND along anterior margin in marginal cell (3)
Y - California geographic region - See explantion for counties
 Zz Do not show this character again (519)
 Sierra Nevada (174)
 Great Central Valley (169)
 Central Western California (161)
 Desert (151)
 Southwestern California (146)
 Northwestern California (133)
 Great Basin (122)
 Cascade Ranges (97)
Y - Subgenera Scrapteropsis and Trachandrena - Length of first flagellomere
 Zz Eliminate these species from the list (476)
 More than three-fourths as long as second (28)
 Three-fourths as long as second or shorter (14)
Y - Subgenus Melandrena - Sterna 3-5 punctures in basal areas
 Zz Eliminate these species from the list (491)
 Present, distinct, scattered throughout but densest near bases of apical areas (16)
 Absent or obscure basally, small punctures limited to narrow line at base of apical area (9)
Y - Subgenus Scaphandrena
 Dark hairs restricted to head - Hind tibial spurs light amber, translucent (13)
 Dark hairs found on head, legs, and abdomen OR abdomen distinctly punctate, clypeus long, and/or abdominal pale hair bands absent - Hind tibial spurs dark amber or dark brown (11)
Y - Subgenus Scrapteropsis, breadth of hind tibia
 Zz Eliminate these species from the list (501)
 Hind tibia broadest at apex (18)
 Hind tibia broader just below middle than at apex (2)
Y - Subgenus Trachandrena
 Zz Eliminate these species from the list (495)
 Propodeal triangle clearly defined by coarse texture and weak ridges along sides, adjacent areas outside triangle more densely sculptured (9)
 Propodeum outside triangle sculptured nearly as coarsely as triangle, boundaries of triangle indistinct (6)
Z - A. aliciae vs A. braccata
 Zz Eliminate these species from the list (518)
 A. ALICIAE - Clypeus protrudes below bottom margins of eyes by about 4/10ths its total length, apex of yellow region convex - Labral process broad, about 3 times as broad as long, not distinctly trapezoidal - Tergum 2 punctures weak but visible, separated by about 3 puncture widths (1)
 A. BRACCATA - Clypeus protrudes below bottom margins of eyes by about 3/10ths its total length, apex of yellow region nearly truncate - Labral process trapezoidal in shape, 2.5 times as broad as long or narrower - Tergum 2 punctures usually obscured, when visible separated by more than 3 puncture widths (1)
Z - A. andrenoides vs A. nida
 Zz Eliminate these species from the list (518)
 A. andrenoides - Base of mandibles with yellow maculae - Propodeal triangle smooth except in basal quarter or less (1)
 A. nida - Base of mandibles black - Propodeal triangle irregular rugulae in basal third or more (1)
Z - A. asteroides vs A. placata
 Zz Eliminate these species from the list (518)
 A. asteroides - First flagellomere equal to or only slightly longer than second and shorter than third - Tergum 2 surface dulled (1)
 A. placata - First flagellomere longer than second and at least as long as third - Tergum 2 surface shiny, smooth or only weakly tessellate (1)
Z - A. barbara, A. carlini, A. confederata, A. dunningi, A. pruni, A. regularis - Species in subgenus Melandrena with punctures on sterna 3-4 absent or obscure basally, with small punctures restricted to narrow line at base of apical area
 Zz Eliminate these species from the list (514)
 A. barbara - Labral process trapezoidal, apical margin emarginate - Clypeus dull throughout - Vertex above lateral ocelli equals 2 or more ocellar diameters - Head hairs entirely pale - Tergal punctures separated by 1-3 puncture widths except on depressed apical margin (1)
 A. carlini - UNIQUE in this group for having dark brown or black hairs on cheek and along inner margin of eye - Labral process trapezoidal, apex entire to weakly emarginate - Clypeus dulled around edges, smoother and shinier in middle - Vertex above lateral ocelli equals 2 or more ocellar diameters - Tergal punctures weak, often obscured by texturing basally where separated by 1-3 puncture widths, sparser apically (1)
 A. confederata - UNIQUE in this group for vertex above lateral ocelli equaling 1.25-1.5 ocellar diameters AND tergal punctures largely obscured by texturing throughout, separated mostly by 2 or more puncture widths - Labral process trapezoidal or rectangular, apical margin weakly emarginate - Clypeus dulled throughout or slightly shinier medially than around edges - Head hairs entirely pale (1)
 A. dunningi - Labral process roughly trapezoidal or semicircular, apical margin evenly rounded - Clypeus dull throughout or only slightly shinier in small medial area - Vertex above lateral ocellus equals 2 or more ocellar diameter - Head hairs entirely pale - Tergal punctures separated by 1-3 puncture widths except on depressed apical margin (1)
 A. pruni - UNIQUE in this group for sternum 6 with large reflexed apical area with dense tuft of long wavy hairs - Labral process trapezoidal, apex entire to weakly emarginate - Head hairs entirely pale - Clypeus dulled around edges, smoother and shinier in middle - Vertex above lateral ocelli equals 2 or more ocellar diameters - Tergal punctures separated mostly by 1-2 puncture widths except along apical margin (1)
 A. regularis - Labral process trapezoidal or with squared-off apex, apical margin entire, straight - Clypeus smooth and shiny medially and apically, dulled only along posterior and lateral margins - Vertex above lateral ocelli equals 2 or more ocellar diameters - Head hairs entirely pale or with some golden-brown hairs on cheek and along inner margin of eye - Tergal punctures weak, separated by 1-2 puncture widths except along depressed apical margin (1)
Z - A. ceanothi, A. forbesii, A. heraclei, A. hippotes, A. mariae, A. nuda, A. rugosa, A. sigmundi, A. spiraeana - Species in subgenus Trachandrena with propodeal triangle clearly defined by coarse texture and weak ridges along sides, adjacent areas outside triangle more densely sculptured
 Zz Eliminate these species from the list (512)
 A. CEANOTHI - First flagellomere about half to two-thirds as long as second - Scutum punctures separated by one puncture width or less throughout - Tergum 1 punctures on dorsal midline separated by distinctly more than one puncture width - Tergum 2 punctures distinct, dense, separated by about one puncture width throughout, punctures of apical area smaller than basally - Tergum 2 with apical depressed area occupying less than half of tergal midline (1)
 A. FORBESII - UNIQUE in this group for having FLAGELLA SHINY BELOW, especially on basal flagellomeres, DIFFICULT to see - Vertex above lateral ocelli equals 1 to 1.5 ocellar diameters - First flagellomere half to two-thirds as long as second - Scutellum punctures distinctly sparser in anterior half, some separated by two or more puncture widths - Tergum 1 punctures on dorsal midline separated by one puncture width or less - Tergum 2 punctures separated by about 1 puncture width or slightly less medially - Sternum 6 apex with distinct V-shaped emargination - Sternum 8 apex slightly expanded and rounded laterally, margin entire or very weakly emarginate (1)
 A. HERACLEI - UNIQUE in this group for terga with YELLOW APICAL HAIR BANDS narrowly interrupted on tergum 2 and complete on terga 3-4 - Vertex above lateral ocelli equals one ocellar diameter or slightly more - First flagellomere half to two-thirds as long as second - Scutum punctures separated by more than one puncture width throughout - Scutellum punctures distinctly sparser in anterior half, some separated by two or more puncture widths - Tergum 1 punctures on dorsal midline separated by one puncture width or less - Tergum 2 with punctures separated by one puncture width, slightly more or slightly less, punctures immediately anterior to depressed area sparser than elsewhere - Sternum 6 apex with shallow, rounded emargination - Sternum 8 apex slightly expanded and rounded laterally, margin entire or very weakly emarginate (1)
 A. HIPPOTES - UNIQUE in this group for distinct YELLOW-ORANGE TO RED COLOR OF HIND TIBIA and tarsi - Vertex above lateral ocelli equals one ocellar diameter or slightly more - First flagellomere half to two-thirds as long as second - Scutellum punctures slightly to distinctly sparser in anterior half, some separated by one or more puncture widths - Tergum 1 punctures on dorsal midline separated by about one puncture width - Tergum 2 with depressed apical area occupying less than half of tergal length, punctures separated by one puncture width, slightly more or slightly less, throughout - Sternum 6 apex with distinct V-shaped emargination - Sternum 8 apex markedly expanded and slightly angular laterally, margin entire to very weakly emarginate (1)
 A. MARIAE - UNIQUE in this group for ABDOMEN OFTEN RED or red in part, although eastern specimens may be all dark - Vertex above lateral ocelli equals one ocellar diameter or slightly more - First flagellomere about three-fourths as long as second - Scutellum punctures distinctly sparser in anterior half, some separated by more than two puncture widths - Tergum 1 punctures on dorsal midline separated by half to 2 puncture widths - Tergum 2 with punctures separated by one puncture width or less - Sternum 6 apex with broad, rounded emargination - Sternum 8 very slightly expanded and rounded laterally, margin entire (1)
 A. NUDA - UNIQUE in this group for COMBINATION OF relatively sparse punctures on rear third of scutum but scutellum punctures dense - Vertex above lateral ocelli equals one ocellar diameter or less - First flagellomere half to two-thirds as long as second - Scutellum punctures not distinctly sparser in anterior half, usually separated by one puncture width or less - Tergum 1 punctures on dorsal midline separated by 1-3 puncture widths - Tergum 2 with depressed apical area occupying half or more of tergal length, punctures separated by one puncture width or less basally, distinctly sparser apically - Sternum 6 apex with broad, rounded or V-shaped emargination - Sternum 8 apex slightly expanded and rounded laterally, margin emarginate (1)
 A. RUGOSA - UNIQUE in this group for SCUTUM MIDLINE DISTINCTLY IMPRESSED in anterior third - Vertex above lateral ocelli equals one ocellar diameter or less - First flagellomere half to two-thirds as long as second - Scutellum punctures not distinctly sparser in anterior half, usually separated by one puncture width or less - Tergum 1 punctures on dorsal midline separated by distinctly 1 to 2 puncture width - Tergum 2 with depressed apical area occupying half or less of tergal length, punctures often separated by about one puncture width or slightly more throughout - Sternum 6 margin nearly straight across or sinuous - Sternum 8 apex slightly expanded and rounded laterally, margin entire or very weakly emarginate (1)
 A. SIGMUNDI - Vertex above lateral ocelli equals 1 to 1.5 ocellar diameters - Scutellum punctures not or only slightly sparser in anterior half, separated by two puncture widths or fewer - Tergum 1 punctures on dorsal midline usually separated by 1 to 2 puncture widths - Tergum 2 with punctures separated by 1-3 puncture widths medially - Sternum 6 margin nearly straight across or sinuous - Sternum 8 apex markedly expanded and slightly angular laterally, margin entire to very weakly emarginate (1)
 A. SPIRAEANA - Body length usually 7-9 mm - First flagellomere about half to two-thirds as long as second - Tergum 1 punctures on dorsal midline separated by distinctly more than one puncture width - Tergum 2 punctures fine, sparse, basally separated by distinctly more than one puncture width, apical area punctures sparse and also fine, sometimes not detectable - Tergum 2 with apical depressed area occupying at about half of tergal midline, occasionally depressed area poorly defined and distinguished mainly by sparser punctation (1)
Z - A. ceanothi, A. hippotes, A. miranda, A. quintilis, A. rehni, A. spiraeana, A. virginiana - Species in subgenus Trachandrena with propodeum outside triangle sculptured nearly as coarsely as triangle, boundaries of triangle indistinct
 Zz Eliminate these species from the list (513)
 A. MIRANDA and A. VIRGINIANA - Vertex above lateral ocelli equals 1.5 ocellar diameters or more - First flagellomere about three-fourths as long as second - Scutum hairs white to very pale yellow - Scutum punctures not distinctly sparser in rear third, punctures separated by one puncture width or less throughout - Scutellum punctures not distinctly sparser in anterior half, usually separated by one puncture width or less - Tergum 1 punctures along dorsal midline minute and separated by about one to less than half a puncture width - Tergum 2 punctures on depressed area midline never touching, separated by more than one-fourth of a puncture width - Terga 3-4 with apical hair bands broadly interrupted - A. miranda and A. virginiana are distinguished in another character (2)
 A. CEANOTHI - Body length usually 8-11 mm - Vertex above lateral ocelli equals one ocellar diameter or slightly more - First flagellomere half to two-thirds as long as second - Scutum punctures distinctly sparser in rear third where separated by more than 2 puncture widths - Scutellum punctures not distinctly sparser in anterior half, usually separated by one puncture width or less - Tergum 1 punctures along dorsal midline distinct and separated by distinctly more than one puncture width - Tergum 2 punctures distinct, dense, separated by about one puncture width throughout, punctures of apical area smaller, apical depressed area occupying less than half of tergal midline (1)
 A. HIPPOTES - UNIQUE in this group for distinct YELLOW-ORANGE TO RED COLOR OF HIND TIBIA and tarsi - Vertex above lateral ocelli equals one ocellar diameter or slightly more - First flagellomere half to two-thirds as long as second - Scutellum punctures slightly to distinctly sparser in anterior half, some separated by one or more puncture widths - Tergum 1 punctures on dorsal midline separated by about one puncture width - Tergum 2 with depressed apical area occupying less than half of tergal length, punctures separated by one puncture width, slightly more or slightly less, throughout - Sternum 6 apex with distinct V-shaped emargination - Sternum 8 apex markedly expanded and slightly angular laterally, margin entire to very weakly emarginate (1)
 A. QUINTILIS - Vertex above lateral ocelli equals 1.5 ocellar diameters or more - First flagellomere about three-fourths as long as second - Scutum hairs pale yellow - Scutum punctures not distinctly sparser in rear third, punctures separated by one puncture width or less throughout - Scutellum punctures not distinctly sparser in anterior half, usually separated by one puncture width or less - Tergum 1 punctures along dorsal midline distinct and separated by about one to less than half a puncture width - Tergum 2 punctures on depressed area midline separated by one-fourth of a puncture width or less, often touching - Terga with apical hair bands usually complete on terga 3 and 4, usually narrowly interrupted on tergum 2 and occasionally on tergum 3 (1)
 A. REHNI - UNIQUE in this group for STERNUM 6 APEX KNOB-LIKE, distinctly reflexed at right angle AND apex bowed outward forming a hairy swelling - Vertex above lateral ocelli equals 1.5 ocellar diameters or more - First flagellomere half to two-thirds as long as second - Scutum punctures slightly sparser in rear third, some separated by up to 2 puncture widths - Scutellum punctures not distinctly sparser in anterior half, usually separated by one puncture width or less - Terga 1 and 2 punctures along dorsal midline minute and separated by distinctly more than one puncture width (1)
 A. SPIRAEANA - Body length usually 7-9 mm - Vertex above lateral ocelli equals one ocellar diameter, slightly more or slightly less - First flagellomere half to two-thirds as long as second - Scutum punctures distinctly sparser in rear third where separated by more than 2 puncture widths - Scutellum punctures not distinctly sparser in anterior half, usually separated by one puncture width or less - Tergum 1 punctures along dorsal midline minute and separated by distinctly more than one puncture width - Tergum 2 punctures fine, sparse, basally separated by distinctly more than one puncture width, apical area punctures indistinct or absent, when present extremely fine, sparse - Tergum 2 with apical depressed area occupying at least half of tergal midline, occasionally depressed area poorly defined and distinguished mainly by sparser punctation (1)
Z - A. commoda, A. confederata, A. dolomellea, A. hilaris, A. illini, A. lupinorum, A. nivalis, A. obscuripennis, A. sayi, A. vicina - Species in subgenus Melandrena with punctures on sterna 3-4 distinct throughout sterna but densest near bases of apical areas
 Zz Eliminate these species from the list (511)
 A. COMMODA - UNIQUE in this group for flagellomere 2 NOT longer than wide - Hairs on face and thorax pale yellow to orangish - Labral process trapezoidal, without punctures, apical margin weakly emarginate to emarginate - Clypeus slightly smoother medially than around edges but never shiny and mirror-like - Clypeus with hairs in center about as dense as in parocular area - Terga 2-3 WITH noticeable but thin apical hair patches at far sides (1)
 A. CONFEDERATA - UNIQUE in this group for vertex above lateral ocelli equaling 1.25-1.5 ocellar diameters AND tergal punctures largely obscured by texturing throughout, separated mostly by 2 or more puncture widths - Hairs of face and thorax white to pale yellow - Labral process trapezoidal or rectangular, apical margin weakly emarginate - Clypeus dulled throughout or slightly shinier medially than around edges - Clypeus with hairs in center about as dense as in parocular area - Terga 2-3 WITHOUT noticeable apical hair patches at far sides (1)
 A. HILARIS - Hairs on face and thorax yellow to orangish-yellow - Labral process trapezoidal, without punctures, apical margin entire or weakly emarginate - Clypeus smooth and shiny except along posterior and lateral margins - Clypeus with hairs in center absent or distinctly sparser than in parocular area - Ventral margin of sides of propodeum with weak rugulae in posterior third to half - Terga 2-3 WITH noticeable but thin apical hair patches at far sides (1)
 A. ILLINI - UNIQUE in this group for labral process distinctly emarginate with broad V-shaped to rounded indentation, with several small punctures near apex - UNIQUE along with A. sayi for propodeal triangle abruptly turned down onto rear face of propodeum and with 1-3 weak transverse ridges at turning point - Hairs on face and thorax yellow to orangish-yellow - Clypeus slightly smoother medially than around edges but never shiny and mirror-like - Clypeus with hairs in center about as dense as in parocular area - Ventral margin of sides of propodeum with distinct rugulae only in posterior third - Terga 2-3 WITH OR WITHOUT noticeable but thin apical hair patches at far sides (1)
 A. LUPINORUM - UNIQUE in this group for sometimes having black hairs above compound eyes, hairs of face and thorax otherwise white to orangish - Labral process trapezoidal, apical margin emarginate, without punctures - Clypeus relatively shiny in half or more of median area - Clypeus with hairs in center about as dense as in parocular area - Terga 2-3 WITH OR WITHOUT noticeable but thin apical hair patches at far sides, hairs sometimes dark (1)
 A. NIVALIS - UNIQUE in this group for sternum 8 with bidentate apical margin, with deep V-shaped indentation - Hairs on face and thorax of specimens from east of the Rocky Mountains white to very pale yellow, specimens from the Rockies westward with dark hairs on face and sides of thorax - Labral process trapezoidal, apical margin emarginate, without punctures - Clypeus smooth and shiny except along posterior and lateral margins - Clypeus with hairs in center absent or distinctly sparser than in parocular area - Terga 2-3 WITHOUT noticeable but thin apical hair patches at far sides (1)
 A. OBSCURIPENNIS - UNIQUE in this group for having wing membranes brown except at bases, visible to the naked eye- Hairs on face and thorax pale yellow to orangish - Labral process trapezoidal, distinctly emarginate, without punctures - Clypeus relatively shiny in half or more of median area - Clypeus with hairs in center slightly sparser than in parocular area - Terga 2-3 WITHOUT noticeable but thin apical hair patches at far sides (1)
 A. SAYI - UNIQUE along with A. illini for propodeal triangle abruptly turned down onto rear face of propodeum and with 1-3 weak transverse ridges at turning point - Hairs on face and thorax white to very pale yellow - Labral process entire or rarely very weakly emarginate, with no or only 1-2 punctures apically - Clypeus smooth and shiny except along posterior and lateral margins - Clypeus with hairs in center absent or distinctly sparser than in parocular area - Ventral margin of sides of propodeum with distinct rugulae in posterior two-thirds or more - Terga 2-3 WITH or WITHOUT noticeable but thin apical hair patches at far sides (1)
 A. VICINA - Hairs on face and thorax white to orangish-yellow - Labral process entire or weakly emarginate, without punctures - Clypeus slightly shinier medially to smooth and shiny except along posterior and lateral margins - Clypeus with hairs in center about as dense as in parocular area - Ventral margin of sides of propodeum with distinct rugulae only in posterior third - Terga 2-3 WITHOUT noticeable but thin apical hair patches at far sides (1)
 A. dolomellea - Still being developed (1)
Z - A. cornelli, A. macoupinensis, A. mandibularis, A. milwaukeensis, A. rufosignata, A. tridens - eastern species with dark face and basal tooth on mandible
 Zz Eliminate these species from the list (513)
 A. cornelli - Head, face, hairs entirely pale - Head, malar space 1- 2 times wider than the eye margin - Head, first flagellomere about 1.5 - 1.75 as long as second and longer than third, this is the primary way of distinguishing it from A. mandibularis - Abdomen, S6, flat or only slightly upturned, long hairs present, but not as in A. macoupinensis (1)
 A. macoupinensis - Head, face hairs entirely pale - Head, malar space, 1-1.5 times the eye margin - Head, first flagellomere about 1.25-1.50 times as long as second and slightly longer as third - Abdomen, S6, the elevated, prow-like apex is covered with a UNIQUE DENSE tuft of hairs that curve over the end of the end of S6 and looks like a small, blond, teased, hairsprayed hairdo (1)
 A. mandibularis - Head, face hairs entirely pale - Head, malar space 1-1.5 times the width of the eye margin - Head, first flagellomere equal or slightly longer than second and about as long as third - Abdomen, S6, flat or only slightly upturned, long hairs present, but not as in A. macoupinensis (1)
 A. milwaukeensis - Head, face, usually with a small set of dark hairs that run along the inside of the compound eye from above the antennae to just above the top of the compound eye , but sometimes these dark hairs are absent - Head, malar space 2 or more times greater than the eye margin - Head, first flagellomere approximately 1.5 times as long as second and longer than third - Abdomen, S6, prowlike and slightly elevated, long hairs present, but not as in A. macoupinensis - Abdomen, T3-5 and S3-5 UNIQUELY covered in SHORT DARK HAIRS, the other species have only pale hairs (1)
 A. rufosignata - Head, face, usually with a small set of dark hairs that run along the inside of the compound eye the start varying from the level of the clypeus to above the antennae to just above the top of the compound eye - Head, malar space distinctly longer than twice eye margin - Head, first flagellomere about equal or slightly longer than second and about as long as third - Sternum 6 apex without dense tuft of hairs - Abdomen, S6, flat or only slightly upturned, long hairs present, but not as in A. macoupinensis (1)
 A. tridens - Head, face, usually with a small set of dark hairs that run along the inside of the compound eye the start varying from the level of the clypeus to above the antennae to just above the top of the compound eye - Head, malar space 1-2 times the eye margin - Head, first flagellomere about 1.25 - 1.5 times as long as second - Abdomen, S6, UNIQUE in that the apex is strongly reflexed or bent at nearly 90 degress like a piece of sheet metal the center is strongly concave leaving the sides projecting as two rounded, dog ear like lobes, long hairs present, but not as in A. macoupinensis (1)
Z - A. crataegi vs A. fenningeri
 None of these apply (518)
 A. crataegi - The labral process is straight to slightly emarginate with the emargination creating broadly rounded outer edges such that these outer lobes are equal to one-third or more of the latitudinal width of the labral process - Pits on the scutum are readily visible due to the combined relatively low tessellation and the deepness of the pits, with pit density uniformly one pit diameter or less - Pit density in the apically impressed rim of T2 about equal to that of the basal area - There are long, off-white hairs present basal to the reflexed rim of S6, appearing to reach over the reflexed rim and very weakly cover it due to the density of the hairs being only slightly higher here than elsewhere on S6 (1)
 A. fenningeri - The labral process is bidentate, forming narrowly rounded lateral edges or tips equal to less than one-fourth the latitudinal width of the labral process, forming a strong, inverted U-shaped concavity in the center of the labral process - Pits on scutum are difficult to see due to heavy tessellation and dulling of the surface and these pits relative shallowness, when these pits are evident they display variable interpit distances averaging approximately one pit diameter - Abdomen, T2, pit density in the apically impressed rim area DISTINCTLY LOWER than in the basal area - In contrast to A. crataegi, the hairs on the apical rim of S6 are shorter and off-white to yellow, denser than elsewhere on S6, and arising from on the reflexed apical rim itself (1)
Z - A. cressonii - subspecies
 Zz Eliminate these species from the list (517)
 A. cressonii cressonii - Legs usually dark, rarely red - Tergum 2 with apical hair band broadly interrupted, tergum 3 with complete or narrowly interrupted hair band (1)
 A. cressonii infasciata - Legs dark - Terga with apical hair bands absent or present only on lateral edges (1)
 A. cressonii kansensis - Legs with hind tibia and tarsi bright orange or red - Tergum 2 with apical hair band narrowly interrupted, tergum 3 hair band complete or extremely narrowly interrupted (1)
Z - A. daeckei vs A. ilicis
 Zz Eliminate these species from the list (518)
 A. daeckei - Galea dull - Scutum punctures between parapsidal lines separated by 1 or more punctures (1)
 A. ilicis - Galea shiny - Scutum punctures between parapsidal lines separated by distinctly less than 1 puncture width (1)
Z - A. forbesii vs others
 Zz Eliminate these species from the list (476)
 Others - Flagellomeres dulled throughout (44)
 A. forbesii - Flagellomeres shiny below, at least on basal flagellomeres (1)
Z - A. fragilis, A. integra, A. persimulata, A. platyparia
 Zz Eliminate these species from the list (516)
 A. fragilis - UNIQUE in this group for clypeus with free apical margin with broad, shallow, V-shaped emargination, lateral corners usually acutely pointed when viewed from below AND sternum 4 with only a comparatively weak fringe of straight hairs extending only about one-third of length of sternum 5 - Clypeus surface with small, widely spaced, but distinct punctures, uniformly moderately shiny or shinier in apical half - Carina along rear edge of cheek usually extends full height of head (1)
 A. integra - UNIQUE in this group for clypeus surface virtually impunctate, punctures entirely absent or very shallow and difficult to detect, textured throughout but slightly shinier in middle third than around posterior and lateral edges - Clypeus with free apical margin with extremely shallow rounded indentation, lateral corners squared off when viewed from below - Carina along rear edge of cheek usually extends full height of head - Sternum 4 with long fringe of straight or slightly curled hairs extending half or more of the length of sternum 5 (1)
 A. persimulata - UNIQUE in this group for carina along rear edge of cheek incomplete, distinct only in upper third of head - Clypeus surface with small but distinct punctures, surface uniformly dulled throughout - Clypeus with free apical margin with broad, shallow indentation, lateral corners squared off when viewed from below - Sternum 4 with long fringe of straight or slightly curled hairs extending half or more of the length of sternum 5 (1)
 A. platyparia - Clypeus surface with small but distinct punctures, surface usually shinier medially than at lateral angles - Clypeus with free apical margin with broad V-shaped or rounded emargination, lateral corners squared off when viewed from below - Carina along rear edge of cheek usually extends full height of head - Sternum 4 with long fringe of straight or slightly curled hairs extending half or more of the length of sternum 5 (1)
Z - A. hilaris, A. illini, A. sayi, A. vicina
 Zz Eliminate these species from the list (515)
 A. hilaris - Labral process entire or weakly emarginate, without punctures - Hairs on face and thorax yellow to orangish-yellow - Clypeus with hairs in center absent or distinctly sparser than in parocular area - Ventral margin of sides of propodeum with weak rugulae in posterior third to half (1)
 A. illini - Labral process distinctly emarginate with a broad V-shaped indentation, with several small punctures near apex - Hairs on face and thorax yellow to orangish-yellow - Clypeus with hairs in center about as dense as in parocular area - Apex of sternum 8 truncate, with sharp angles laterally - Ventral margin of sides of propodeum with distinct rugulae only in posterior third (1)
 A. sayi - Labral process entire or rarely very weakly emarginate, with no or only 1-2 punctures apically - Hairs on face and thorax white to very pale yellow - Clypeus with hairs in center absent or distinctly sparser than in parocular area - Ventral margin of sides of propodeum with distinct rugulae in at least two-thirds (1)
 A. vicina - Labral process entire or weakly emarginate, without punctures - Hairs on face and thorax can vary among specimens from dirty white to yellow to orangish-yellow - Clypeus with hairs in center about as dense as in parocular area - Ventral margin of sides of propodeum with distinct rugulae only in posterior third (1)
Z - A. hippotes vs A. kalmiae
 Zz Eliminate these species from the list (518)
 A. hippotes - Tarsi and hind tibia red to orange - Transverse ridge of propodeal triangle usually distinct (1)
 A. kalmiae - Tarsi and tibia dark - Transverse ridge of propodeal triangle weak or absent (1)
Z - A. illinoiensis, A. nigrae, A. salictaria
 Zz Eliminate these species from the list (517)
 A. illinoiensis - Body usually at least 8 mm in length - Hind leg tarsi may be paler than tibia but not orange - Vein r at least two vein widths in length - Sternum 6 with distinct tuft of long, white hairs - Tip of penis valve pointed in lateral view, not usually visible when genitalia retracted (1)
 A. nigrae - Body often less than 8 mm in length - Hind leg tarsi and sometimes apex of tibia orange, contrasting with basal segments - Vein r at least two vein widths in length - Sternum 6 without distinct tuft of hairs - Tip of penis valve pointed in lateral view, not usually visible when genitalia retracted (1)
 A. salictaria - Body usually at least 8 mm in length - Hind leg tarsi dark like tibia - Vein r extremely short, one or at most two vein widths in length - Sternum 6 without distinct tuft of hairs - Tip of penis valve rounded in lateral view, usually visible even with genitalia retracted (1)
Z - A. imitatrix vs A. morrisonella
 Zz Eliminate these species from the list (518)
 A. imitatrix - Tergum 2 usually dulled throughout by fine tessellation - Sternum 8 apex entire to very weakly emarginate (1)
 A. morrisonella - Tergum 2 smooth and shiny except at extreme base - Sternum 8 apex distinctly emarginate - NOTE: No description of the male of this species has been published and it has been suggested that the species may be simply a variant of A. imitatrix (1)
Z - A. macra vs A. perplexa
 None of these apply (518)
 A. macra - Mandibles long such that, with the mandibles closed, tips of mandibles exceed clypeus midline by one-third to one-fourth of their total length, forming a weak X which most often must be confirmed with a ventral view - F1 nearly as long as F2 F3 - The apically impressed area of T2 is of equal pit density to the basal area of the segment (1)
 A. perplexa - Mandibles extremely long such that, with the mandibles closed, tips of mandibles exceed the clypeus midline by two-fifths to one-half of their total length, forming a very strong X which may often be visible from an anterior view - F1 about as long as F2, much shorter than F2 F3 - The apically impressed area of T2 is of far lesser pit density in comparison to the basal area of the segment (1)
Z - A. melanochroa, A. nasonii, A. phaceliae, A. wheeleri
 Zz Eliminate these species from the list (516)
 A. melanochroa - Clypeus shiny apically and dulled in basal third - First flagellomere longer than second and third - Mesepisternum without tubercle - Propodeal triangle uniformly rugose throughout, slightly but distinctly coarser than adjacent areas outside triangle, basal longitudinal striations absent - Sternum 6 flat to reflexed apically with broad curve to apical half - Sternum 6 apical margin with V-shaped emargination (1)
 A. nasonii - Clypeus dull throughout - Flagellomeres 1-3 very roughly equal in length - Mesepisternum in 90 percent of specimens with pleural signum slightly raised, forming a TUBERCLE or bump on ventral surface just BELOW where mesepisternum turns inward- Propodeal triangle usually with longitudinal striations in basal half and with 1-3 weak transverse ridges near apex where propodeum turns down posteriorly, when basal striations are absent, triangle sculpturing is similar to or finer than adjacent areas outside triangle - Sternum 6 flat or only very slightly reflexed apically - Sternum 6 apical margin with shallow, rounded emargination - Common (1)
 A. phaceliae - Clypeus dull throughout - First flagellomere slightly longer than second and about equal to third - Mesepisternum without tubercle - Propodeal triangle rugose in basal half to three-fourths, slightly but distinctly coarser than adjacent areas outside triangle, without longitudinal striations or with a single medial striation, apical third or so more finely sculptured - Sternum 6 flat or only very slightly reflexed apically - Sternum 6 apical margin straight or with shallow, rounded emargination (1)
 A. wheeleri - Clypeus usually shinier apically and dulled in basal half or less, occasionally dulled throughout - First flagellomere DISTINCTLY longer than second and about equal to third - Mesepisternum without tubercle as in A. nasonii - Propodeal triangle uniformly rugose or with weak longitudinal striations basally, more finely sculptured in apical third such that point where propodeum turns down posteriorly is smooth and without weak transverse ridges - Sternum 6 flat or only very slightly reflexed apically - Sternum 6 apical margin with shallow, rounded emargination - Tough to tell from A. nasonii, and much rarer (1)
Z - A. miranda vs A. virginiana
 Zz Eliminate these species from the list (518)
 A. miranda - Punctures above middle ocellus irregularly shaped, so dense as to be touching and may be confused with coarse texturing - Top of foveal area with fine punctures extending above a line drawn between tops of lateral ocellus and compound eye - Genal area punctures more or less uniform in size, although texturing posteriorly is coarser - Tergum 2 with depressed apical area usually occupying half of tergal length (1)
 A. virginiana - Punctures above middle ocellus round, closely spaced but distinct and not likely to be confused with coarse texturing - Top of foveal area with fine punctures extending up to or below a line drawn between tops of lateral ocellus and compound eye - Genal area immediately behind eye with punctures sparser and smaller than punctures interspersed with rugulae in posterior region - Tergum 2 with depressed apical area occupying less than half of tergal length (1)
Z - A. placata vs A. simplex
 Zz Eliminate these species from the list (518)
 A. placata - Third flagellomere distinctly longer than second - Tergum 2 midline smooth and shiny except at base (1)
 A. simplex - Third flagellomere about as long as second - Tergum 2 midline at least weakly tessellate throughout (1)
Z- A. alleghaniensis vs A. atlantica - Indistinguishable except by geographic range - Specimens from the Eastern Piedmont areas could be either
 Zz Eliminate these species from the list (518)
 A. alleghaniensis - Occurs from just east of the Appalachian Mountains to the west and north (1)
 A. atlantica - Occurs throughout the coastal plain provinces from Southern New Jersey south along the Atlantic Coast and to the west along the Gulf Coast (1)
ZZ - Species coded - for internal use only
 Not yet coded (520)
 Coded from description (95)
 Coded (19)
 Coded from junior type (13)
 Coded from primary type (2)
 Coded as far as possible from description and with subgeneric characters (1)
Zz - Type museums - for internal use only
 z No male types (128)
 US-IL-INHS (106)
 US-CA-CAS (102)
 US-DC-USNM (79)
 US-CA-UCR (61)
 US-CA-UCB (55)
 US-KS-SEMC (44)
 US-CA-UCD (31)
 US-PA-ANSP (21)
 US-UT-EMUS (20)
 US-NY-AMNH (19)
 US-MI-MSUC (16)
 US-CA-LACM (14)
 US-OR-OSAC (10)
 US-NE-UNSM (9)
 ENG-BMNH (8)
 US-NC-NCSU (7)
 CAN-CNC (5)
 z Unknown (5)
 US-AZ-UAIC (4)
 US-NY-CUIC (4)
 US-CA-CPUP (3)
 US-OH-OSUC (3)
 US-CA-SJSC (2)
 US-CA-UOP (2)
 US-CO-UCNH (2)
 US-FL-FSCA (2)
 US-KS-KSUC (2)
 US-PA-CMNH (2)
 CAN-PMQ (1)
 GER-SMFD (1)
 GER-ZMHB (1)
 SWED-MZLU (1)
 SWITZ-NHMB (1)
 US-AZ-NAUF (1)
 US-GA-GSU (1)
 US-IL-SIUC (1)
 US-MO-UMRM (1)
 US-OU (1)
 US-TX-CTMI (1)