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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 eremophila  [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
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]
Male  [popup]
Stylopized specimen  [popup]


REMAINING (number with state)
A. carlini vs A. regularis vs A. vicina
 A. carlini - Head, Clypeus with a clear UNPITTED longitudinal line running down the center, wider in A. carlini than A. vicina - Body, hairs, completely black on cheek, extending upward over half of the mesepisternum, hind femur scopal hairs either completely black or up to half white - Abdomen, T2, pitting in the central, basal half readily visible, surface smooth, and pits relatively large and apparent under even modest magnification - Legs, hind, trochanter hair length UNIFORM throughout - Pygidial plate broad, often truncate at the tip forming a much wide rounded triangle (1)
 A. regularis - Head, Clypeus with nearly UNIFORM pitting - Body, hairs, much less extensively black on cheek, mesepisternum, hind femur than A. carlini often the same as A. vicina thought the scopal hairs on the femur are almost all pale - Abdomen, T2, pitting in the central, basal half difficult to see and apparent only under magnification as the pits are tiny and immersed amidst a sea of microscopic topography that dulls the surface - Legs, hind, trochanter hair length UNIFORM throughout - Pygidial plate VERY NARROW forming and acute arrow-head shape (1)
 A. vicina - Head, Clypeus with a clear UNPITTED longitudinal line running down the center, narrower than A. carlini and sometimes difficult to discern - Body, hairs, pale on cheek, pale on the mesepisternum, hind femur scopal hairs either completely black or with vague paler hairs in the center - Abdomen, T2, pitting in the central, basal half readily visible, surface smooth, and pits relatively large, though not quite as large as A. carlini, and apparent under even modest magnification - Legs, hind, trochanter hair length DECREASES dramatically towards the base - Pygidial plate moderately wide, in between the other two species, essentially a wide triangle - I direct comparison slightly larger than the other 2 species (1)
A. uvulariae vs. A. ziziaeformis
 A. uvulariae - Scutum, central area, shiny and glossy, without any finely engraved lines to dull the surface, sides of scutum can be 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 (519)
 10 (397)
 9 (373)
 11 (371)
 8 (305)
 12 (304)
 13 (202)
 7 (194)
 14 (126)
 6 (81)
 15 (71)
 16 (32)
 5 (29)
 17 (9)
 4 (9)
 18 (3)
Flight Season - Month
 5. May (375)
 4. April (356)
 6. June (326)
 3. March (306)
 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
 4. As long as or longer than second plus third flagellomeres together (395)
 3. Longer than second flagellomere but not as long as second plus third (201)
 2. About as long as second flagellomere (6)
 1. Shorter than second flagellomere (1)
Head, clypeus and parocular areas, color of integument
 Both entirely dark (462)
 One or both with at least some metallic reflections (60)
 UNCOMMON: Both with at least some yellow (12)
 UNCOMMON: Clypeus with at least some yellow, parocular areas dark (12)
 UNCOMMON: Clypeus dark, parocular areas with at least some yellow (4)
Head, clypeus, impunctate midline
 Absent (279)
 Present (265)
Head, clypeus, shape in profile
 2. Normal, gently curved, but not bulging (357)
 3. Domed and bulging (46)
 1. Flat or nearly so, at most slightly bending near margin (42)
Head, clypeus, surface texture between punctures
 SHINY in center or apically and DULLED at least along dorsal and lateral margins (342)
 DULLED throughout (226)
 SHINY throughout (116)
Head, facial fovea, color of hair
 All pale, white to yellow (284)
 Dark throughout, brown to black (136)
 Dark above, pale below (133)
 UNCOMMON: Pale with longer, scattered dark hairs (1)
Head, facial fovea, depth in upper half of fovea
 Moderate, impressed but not deeply so (255)
 Shallow, not noticeably impressed (232)
 Deep, sides of fovea cutting down from surface of face at nearly a right angle (70)
Head, facial fovea, length
 Long, reaching to below level of lower margin of antennal socket, sometimes to level of top margin of clypeus (302)
 Moderate, reaching level of lower margin of antennal socket (164)
 Extremely long, reaching to below level of top margin of clypeus (121)
 Moderate, reaching level of middle of antennal socket (118)
 Short, reaching level of upper margin of antennal socket (49)
 Very short, not reaching level of upper margin of antennal socket (19)
Head, facial fovea, minimum distance to lateral ocellus
 1. LESS THAN one ocellar diameter (297)
 2. ABOUT ONE ocellar diameter (237)
 3. MORE THAN one ocellar diameter (150)
Head, facial fovea, width at level of antennal sockets - or at bottom for species with short fovea
 BROAD, fovea broader than antennal socket (222)
 MODERATE, fovea about as wide as antennal socket (217)
 NARROW, fovea narrower than antennal socket AND fovea near eye margin (133)
 NARROW, fovea narrower than antennal socket AND fovea separated from eye margin by at least half its own width (26)
Head, facial quadrangle
 2. QUADRATE, about as broad as long (292)
 1. BROADER than long (205)
 3. LONGER than broad (170)
Head, galea, formation - NOTE that you will not be able to see this character unless the mouthparts have been pulled
 Normal, broad at base and not spear-shaped, surface can be shiny or dull (503)
 Narrow and pointed, spear-shaped, apical half with outer margin straight AND surface at least partly shiny (11)
 Narrow and pointed, spear-shaped, apical half with outer margin straight AND surface dull (8)
Head, labral process, length
 Long, half length of labrum or longer (243)
 Moderate, between one-third and one-half length of labrum (206)
 Short, one-third labral length or shorter (51)
Head, labral process, margin
 2. Weakly emarginate (245)
 1. Entire, edge continuous from side to side (244)
 3. Emarginate but not bidentate (126)
 4. Bidentate - Note that in many bidentate species you have to turn the specimen almost upside down to see the bidentate tip, which is at times not visible from above (107)
 5. Pointed (26)
 6. UNCOMMON - With a median projection (1)
Head, malar area, minimum length
 2. Short, between one and two times the eye rim (235)
 1. Extremely short, no wider than rim of compound eye (216)
 3. Moderate, more than twice the eye rim but not 1/5 as long as broad (93)
 4. Long, 1/5 to 1/3 as long as broad (53)
 5. Extremely long, more than 1/3 as long as broad (16)
Head, mandible, apex
 Bidentate (516)
 UNCOMMON: Tridentate (3)
Head, mandible, formation along ventral margin
 Lamella present ventrobasally, not distinctly broadened near mandible base (210)
 Lamella present ventrobasally, distinctly broadened near mandible base (120)
 UNCOMMON: Broadens smoothly toward base, without tooth, angle or lamella (66)
 Mandible with strong ventrobasal angle near its base, lamella usually present (43)
 UNCOMMON: With small tooth or angle at base near inferior articulation, lamella usually present (20)
Head, maxillary palpus length
 4. Exceeds galea by two palpal segments or slightly less (227)
 5. Exceeds galea by three palpal segments or slightly less (171)
 1. Shorter than galea (77)
 2. Equal in length to galea (51)
 3. Exceeds galea by one palpal segment or slightly less (45)
Head, subgenal coronet
 Present, well-developed (392)
 Poorly developed (12)
 Absent (10)
Head, vertex height, distance from lateral ocelli to rear margin of head
 2. About 1 ocellar diameter (278)
 1. Less than 1 ocellar diameter (248)
 3. More than 1 to 1.5 ocellar diameters (230)
 4. More than 1.5 to 2 ocellar diameters (65)
 5. Two or more ocellar diameters (37)
Initial inspection
 Normal FEMALE (518)
 Normal MALE (1)
 UNCOMMON: Stylopized (1)
Legs, middle legs, basitarsus width
 Not markedly expanded, as broad as or narrower than hind basitarsus (370)
 Expanded medially, broader than hind basitarsus (60)
Legs, rear legs, femur shape when viewed from below
 Barrel of the femur rounded from side to side, without ridges (513)
 With one or two ridges running at least partway along the length of the femur - Note that ridges can be sharp or weak (9)
Legs, rear legs, rear tibial spurs
 Normal, similar to fore tibial spur, nearly straight and not distinctly broadened near base (443)
 UNCOMMON: Distinctly curved at least in outer half (21)
 Slightly but obviously bent and sometimes slightly twisted about one-third from apex (9)
 Strongly bent at least in outer half AND broadened and flattened near base (9)
 UNCOMMON: With apex sharply hooked (6)
 UNCOMMON: Distinctly curved in at least half of length and sometimes slightly twisted in basal third (3)
Legs, rear legs, tibia shape
 Normal, broader at apex than at midpoint, but at most 1.5 times as wide as basitarsus and scopal hairs along outer margin of tibia long (227)
 Narrow, nearly parallel-sided, scarcely broader at apex than at midpoint (61)
 Cuneate, apex at least 1.5 times as wide as basitarsus AND scopal hairs along outer margin of tibia short and dense, especially apically (49)
Legs, rear legs, tibial scopa, color of hair
 PALE, sometimes with dark hairs extending down outside edge from basitibial plate but not more than half way (332)
 All DARK (115)
 With BOTH dark and pale hair in apical half (91)
Legs, rear legs, tibial scopal hair formation
 1. Hairs simple and unbranched IN CENTER of outside face of tibia, but hairs along outer edges of tibia can be branched or unbranched (328)
 3. Plumose, with many branches per hair (94)
 2. Weakly branched throughout, only 1-3 branches per hair and/or branches very weak (58)
 As in stipator (1)
Legs, rear legs, trochanteral flocculus
 Complete, with long, curled hairs except sometimes at extreme base (397)
 Incomplete, with short, relatively straight, hairs in basal half or more of flocculus (74)
Locality where specimen was collected in Canada
 Zz Do not show this character again (518)
 British Columbia (106)
 Ontario (88)
 Quebec (73)
 Alberta (72)
 Saskatchewan (56)
 Manitoba (52)
 New Brunswick, Nova Scotia or Prince Edward Island (49)
 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 (519)
 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 (519)
 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)
 NJ (107)
 IL (105)
 SD (103)
 WV (103)
 IN (101)
 MD (101)
 DE (100)
 DC (99)
 NY (99)
 OH (99)
 VA (99)
 KY (97)
 NC (97)
 MO (96)
 TN (93)
 KS (92)
 MI (91)
 WI (91)
 CT (90)
 MA (90)
 RI (90)
 SC (90)
 GA (89)
 IA (86)
 MN (82)
 NH (76)
 VT (76)
 ND (74)
 OK (74)
 ME (73)
 AR (58)
 AL (53)
 MS (45)
 LA (36)
 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, color of integument
 1. All DARK, black to reddish-brown, without distinct red or orange coloration or metallic reflections (418)
 3. With FAINT metallic reflections visible with a microscope, otherwise dark (76)
 4. With distinct METALLIC reflections visible to the naked eye (47)
 2. RED or orange, at least in part, without metallic reflections (36)
Metasoma, pygidial plate, internal triangle or ridge
 Present, with median raised or textured triangle or longitudinal ridge (283)
 Absent, surface unmodified (270)
Metasoma, terga 2-4, color of hair, including apical hair bands when present
 All PALE, white, yellow, orange or reddish (392)
 All DARK, black to reddish-brown (91)
 MIXED pale and dark (68)
Metasoma, tergum 2, pale apical hair bands
 2. Narrowly interrupted medially, no more than half of apical margin bare (262)
 3. Broadly interrupted, more than half of apical margin bare (217)
 4. Absent, hair on apical margin not denser than elsewhere (214)
 1. Complete, not interrupted medially (145)
Metasoma, tergum 2, puncture spacing on longitudinal center of segment - Note, ignore puncture patterns along the rim and the very base of the segment
 Absent or indistinct and difficult to see even at high magnification (207)
 Separated by 1-3 puncture widths (192)
 Dense, separated by 1 puncture width or less (111)
 Separated by 3-6 puncture widths (74)
Metasoma, tergum 2, surface texture in middle of tergum
 GRANULAR or with fine lines, usually dull but may still be somewhat shiny (312)
 SMOOTH and SHINY (153)
Region where specimen was collected
 Zz Do not show this character again (518)
 1. United States (477)
 3. Mexico (218)
 2. Canada (165)
 4. South of Mexico (7)
Subgenus - for Andrena experts only
 Zz Do not show this character again (517)
 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 (13)
 Simandrena (11)
 Parandrena (10)
 Derandrena (9)
 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)
This guide is UNDER CONSTRUCTION
 4. Click here to keep all species in the key - note that many western species have not been completely scored so the guide is unlikely to resolve these species completely (517)
 3. Click here to include all species except those rare and potentially invalid species we have not seen - note that many western species haven t 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 (122)
Thorax, color of hair
 All PALE, white, yellow, orange or reddish (390)
 PALE on the dorsal surfaces becoming BLACK on the ventral surfaces (56)
 DARK throughout (43)
 BOTH pale and dark hairs present on dorsum (32)
 Bright ORANGE on dorsal surfaces (27)
 DARK on dorsal surfaces, becoming paler ventrally (19)
 UNCOMMON: Pale on dorsal surfaces with a distinct transverse line of dark hairs along rear margin of scutum (5)
 UNCOMMON: Dorsum with numerous short, dark hairs and scattered long pale hairs, pale hairs laterally (1)
Thorax, color of integument
 Dark (436)
 Weakly metallic, visible through a microscope (52)
 Distinctly metallic, visible to the naked eye (35)
 With at least some red or orange (5)
Thorax, pronotum humeral angle
 Present, but WEAK, with slight angle but not with distinct corners (290)
 ABSENT, rear margin of pronotum smoothly rounded (234)
 Present, distinctly squared off forming CORNERS (112)
Thorax, pronotum, ridge extending down from humeral angle
 1. Absent, no trace of ridge present (344)
 2. Weak but present, apex of ridge rounded, not distinctly angled (131)
 3. Distinct, ridge angular and extending at least half height of pronotum (57)
 4. Distinct AND ridge deeply impressed by a diagonal suture (9)
Thorax, propodeal corbicula, form
 3. Incomplete, without anterior fringe of hairs, internal hairs usually present (313)
 2. Nearly complete, with anterior fringes of hairs and at least a few long internal hairs (103)
 1. Complete, with anterior fringe of hairs, bare internally (69)
 4. Not evident, anterior fringe absent, dorsal hairs not much longer than adjacent thoracic hairs and not curved downward, internal hairs absent or present and intergrading into dorsal hairs (9)
Thorax, propodeal triangle, complete transverse ridge separating dorsal and posterior surfaces - Note that some species may appear to have a ridge but close inspection will show that the ridge is not complete but simply part of the coarse internal triangle structure
 Absent (460)
 Present (39)
 As in stipator (1)
Thorax, propodeal triangle, form of sculpturing
 1. Finely sculptured throughout, tessellate except sometimes rugulate in basal fourth (271)
 2. With fine, irregular rugulae in half or more of triangle (151)
 3. With coarse, irregular rugulae in half or more of triangle (95)
 4. Areolate (48)
 UNCOMMON: With longitudinal rugulae in basal half, tessellate or smooth at apex (43)
 UNCOMMON: With transverse striae in basal half, tessellate or smooth at apex (12)
 As in stipator (1)
Thorax, propodeal triangle, percentage of LENGTH coarsely sculptured
 0 percent - surface uniformly smooth (343)
 5 - 50 percent (296)
 50 - 80 percent (160)
 100 percent - triangle completely filled (100)
Thorax, propodeum, form
 Normal, with distinct dorsal and posterior surfaces (396)
 Sloping gradually from base to apex, without distinct dorsal surface (36)
Thorax, propodeum, texture on posterior surface outside triangle
 Dulled by tessellation or shagreening (292)
 Coarsely and irregularly roughened (94)
 Tessellation extremely fine, surface somewhat shiny (36)
 Areolate (23)
 As in stipator (1)
Thorax, scutum, form of hair
 Long throughout, more than half as long as hairs on mesepisternum (227)
 Short medially, half as long as hairs on mesepisternum, but not mat-like (195)
 Absent or extremely sparse medially, hairs around edges of scutum at least half as long as hairs on mesepisternum, not mat-like, hairs rarely absent laterally (185)
 With both short and long hairs mixed together (58)
 Extremely short, dense, and highly branched throughout, forming a dense mat-like surface (20)
 Absent or extremely sparse medially AND hairs around edges of scutum mat-like, extremely short, dense, and highly branched (11)
Thorax, scutum, punctures between parapsidal lines, except midline area
 Separated by 1 puncture width or less (226)
 Separated by 1-3 puncture widths (192)
 Absent or obscure (125)
 Separated by 3 or more puncture widths (43)
Thorax, scutum, texture
 Dulled throughout, tessellate (236)
 Mostly dull, but somewhat shiny posteromedially where tessellation is weaker (221)
 Smooth and shiny medially, tessellation extremely weak except around edges (76)
 Mostly or entirely dull AND with fine, longitudinal, parallel rugulae (3)
Thorax, tegulae, surface texture in posterior half
 Impunctate (516)
 Punctate (3)
Wing, forewing, vein m-cu meets second submarginal cell
 3. Slightly beyond middle (285)
 4. About two-thirds of the way from base of cell (262)
 2. At middle of cell (236)
 1. Before middle of cell (232)
 5. About three-fourths of the way from base of cell (200)
 6. Near apex of cell (98)
Wings, forewing, number of submarginal cells
 3 (472)
 2 (101)
Wings, forewing, stigma size
 About as broad as prestigma (282)
 Broader than prestigma, but vein r longer than 4 vein widths (255)
 Distinctly broader than prestigma, AND vein r shorter than 4 vein widths (54)
Y - California geographic region - See explantion for counties
 Zz Do not show this character again (518)
 Sierra Nevada (175)
 Great Central Valley (170)
 Central Western California (162)
 Desert (152)
 Southwestern California (148)
 Northwestern California (134)
 Great Basin (122)
 Cascade Ranges (98)
Y - Subgenera Trachandrena and Scrapteropsis - Face above antennal sockets
 Zz Neither Trachandrena nor Scrapteropsis (476)
 1. With distinct longitudinal rugulae obscuring punctures (33)
 2. With weak longitudinal rugulae, punctures prominent (27)
 3. Without rugulae but dulled by coarse texturing (9)
 4. Without rugulae but densely punctate, somewhat shiny (8)
 5. Smooth and shiny, sparsely punctate (3)
Y - Subgenus Andrena s.str. - Tergum 2 form of hairs
 Zz Not Andrena s.str. (480)
 Long, dense hairs covering entire surface of tergum (22)
 Hairs short or, if long, sparse and not covering entire surface of tergum (19)
Y - Subgenus Cnemidandrena - Tergal hair band width
 Zz Not Cnemidandrena (492)
 WIDE, obscuring MORE than one-third of length of tergum 3 (17)
 Relatively NARROW, obscuring one-third or less of tergum 3 length (16)
Y - Subgenus Cnemidandrena - Tergum 5 hair color
 Zz Not Cnemidandrena (492)
 Similar to apical hair bands on anterior terga (17)
 Distinctly darker than apical hair bands on anterior terga (11)
Y - Subgenus Diandrena - Hind tibial scopal hair formation
 Zz Not Diandrena (495)
 Hairs along outer edge of tibia moderately dense and branched (18)
 Hairs along outer edge of tibia sparse and simple (4)
Y - Subgenus Diandrena - Hind wing jugal lobe
 Zz Not Diandrena (495)
 Narrow, indistinct, not separated from vannal lobe by an incision (13)
 Distinct, broad, separated from vannal lobe by an incision (11)
Y - Subgenus Euandrena - Hind wing vannal lobe breadth
 Narrow, at base of excision 1.5 times as broad as the end of cell Cu or narrower (4)
 Broad, at base of excision more than 1.5 times as broad as the end of cell Cu (3)
Y - Subgenus Micrandrena - Form of propodeal triangle sculpturing
 Zz Not Micrandrena (499)
 Propodeal triangle relatively smoothly sculptured throughout, surface similar to adjacent areas outside triangle or only slightly coarser in basal half or less (9)
 Propodeal triangle coarsely sculptured in half or more of triangle, surface distinctly rougher than adjacent areas outside triangle (4)
Y - Subgenus Scaphandrena
 Species in subgenus Scaphandrena with hairs PALE throughout, except sometimes dark on facial fovea, hind tibial bases, and tip of abdomen - Hind tibial spurs usually light amber, translucent (13)
 Species in subgenus Scaphandrena with hairs DARK throughout, except sometimes pale on vertex of head and thoracic dorsum - Hind tibial spurs usually dark amber to dark brown (11)
Y - Subgenus Scaphandrena - Form of tarsal claws
 Zz Not Scaphandrena (516)
 Tarsal claws with subapical tooth (10)
 Tarsal claws without subapical tooth (7)
Y - Subgenus Simandrena - Form of clypeus hairs
 Zz Not Simandrena (510)
 Plumose throughout (5)
 Simple or minutely branched medially, plumose laterally (2)
 Simple throughout or nearly so (1)
Y - Subgenus Trachandrena - Form of facial fovea
 Zz Not Trachandrena (495)
 Broadest portion of fovea less than 2.5 times as wide as narrowest AND widest gap between fovea and eye narrower than scape apex (18)
 Broadest portion of fovea at least 3 times as wide as narrowest AND widest gap between fovea and eye narrower than scape apex (9)
 Broadest portion of fovea at least 3 times as wide as narrowest AND widest gap between fovea and eye equal to or broader than scape apex (4)
Z - A. aculeata vs A. durangoensis
 Neither of these (518)
 A. ACULEATA - Clypeus dulled at least near base area above clypeus dulled (1)
 A. DURANGOENSIS - Clypeus surface shiny throughout area above clypeus shiny, not dulled (1)
Z - A. algida, A. arabis, A. geranii, A. illinoiensis, A. salictaria, A. ziziaeformis
 Zz - All the other Andrena species (514)
 A. ALGIDA - Body length usually 8-10 mm - Integument dark, without metallic reflections - Labral process base about twice as broad as apex, apical margin entire to emarginate - Vein r 3 or more vein widths in length - Tergum 2 somewhat shiny, with weak tessellation and weak punctures separated by 2 or more puncture widths - Tergum 3 with apical hair band weak, absent to narrowly interrupted (1)
 A. ARABIS - UNIQUE in this group for body length usually 9-11 mm AND clypeus slightly flattened in center - Integument dark, without metallic reflections - Labral process base about 2-3 times as broad as apex - Vein r longer than 4 vein widths - Tergum 2 with small but distinct punctures separated by 1-3 puncture widths in basal half - Tergum 3 with apical hair band distinct, complete or weak medially (1)
 A. GERANII - UNIQUE in this group for thorax and abdomen usually with weak blue-green metallic sheen AND propodeal corbicula with dorsal hairs short and not curved down - Body length usually 8-11 mm - Labral process base about twice as broad as apex, apical margin usually emarginate - Vein r longer than 4 vein widths - Tergum 2 with small but distinct punctures separated by 3 or more puncture widths in basal half - Tergum 3 with apical hair band weak, absent to narrowly interrupted (1)
 A. ILLINOIENSIS - Body length usually 7-9 mm - Thorax and abdomen usually dark, without metallic reflections or at most very weak and olive-green or violet - Labral process triangular, apex pointed - Vein r 2-3 vein widths in length - Tergum 2 not punctured - Tergum 3 with apical hair band distinct, thick, complete to weak medially (1)
 A. SALICTARIA - UNIQUE in this group for vein r 1 vein width in length - Body length usually 7-9 mm - Thorax and abdomen usually dark, without metallic reflections or at most very weak and olive-green or violet - Labral process base 2-3 times as broad as apex, apical margin entire - Tergum 2 not punctured - Tergum 3 with apical hair band weak, absent to narrowly interrupted (1)
 A. ZIZIAEFORMIS - Body length usually 6-8 mm - Integument dark, without metallic reflections - Labral process base about 1.5 times as broad as apex, apical margin entire to weakly emarginate - Vein r 2-3 vein widths in length - Tergum 2 with small punctures visible at high magnification, may be obscured by texturing at lower magnification, separated by 1-3 puncture widths in basal half - Tergum 3 with apical hair band narrow, complete to narrowly interrupted (1)
Z - A. alleghaniensis, A. atlantica, A. rubi - Species in subgenus Scrapteropsis with hind femur with one or two distinct ridges or angles ventrally
 All the other Andrena species (517)
 A. ALLEGHANIENSIS - Scutum hairs medially mostly extremely short, stout, and highly plumose, LESS than five times as long as wide, with a few long hairs scattered throughout, hairs longer and denser near edges - Terga 2-4 with apical hair bands absent or extremely weak (1)
 A. ATLANTICA - Scutum hairs long, many times the hair diameter and more than half as long as hairs on mesepisternum - Terga with apical hair bands weak, interrupted medially and not obscuring surface of tergum (1)
 A. RUBI - Scutum hairs medially mostly short, stout, and highly plumose, MORE than five times as long as wide, with a few long hairs scattered throughout, hairs longer and denser near edges - Terga 2-4 with apical hair bands distinct, interrupted on tergum 2 and occasionally tergum 3 (1)
Z - A. amphibola, A. cleodora_cleodora, A. cleodora_melanodora, A. cupreotincta, A. winnemuccana - Species in subgenus Trachandrena with broadest portion of fovea NO MORE THAN 2.5 times as wide as narrowest AND tibial scopal hairs mostly or entirely dark
 None of these apply (515)
 A. AMPHIBOLA - UNIQUE in this group for tergum 1 dorsal surface punctures dense, separated by half to 2 puncture widths throughout dorsal surface and by 1-3 puncture widths on anterior surface of tergum 1 - Face below ocelli with weak rugulae not obscuring punctures - Scutum hairs extremely short, mat-like or almost so, pale to red (1)
 A. CLEODORA_CLEODORA - UNIQUE in this group in having face below ocelli with strong longitudinal rugulae that obscure the punctures AND PALE short hairs on the scutum - Tergum 1 punctures small and sparse, irregularly spaced but usually by three or more puncture widths (1)
 A. CLEODORA_MELANODORA - UNIQUE in this group in having face below ocelli with strong longitudinal rugulae that obscure the punctures AND DARK short hairs on the scutum - Tergum 1 punctures small and sparse, irregularly spaced but usually by three or more puncture widths (1)
 A. CUPREOTINCTA - Face below ocelli smooth and shiny or with weak rugulae not obscuring punctures - Scutum hairs shorter than those of mesepisternum and very dense but not mat-like, pale to red - Tergum 1 punctures separated by 1-3 puncture widths throughout dorsal surface, punctures on anterior surface of tergum sparse, separated by 3 or more puncture widths (1)
 A. WINNEMUCCANA - UNIQUE in this group for tergum 1 punctures separated by 1-2 puncture widths along dorsal midline and distinctly sparser laterally, anterior surface of tergum 1 virtually impunctate - Face below ocelli with weak rugulae not obscuring punctures - Scutum hairs not particularly short or dense, pale (1)
Z - A. andrenoides vs A. nida
 All the other Andrena species (518)
 A. ANDRENOIDES - Eastern specimens entirely black, prairie specimens often with red abdomen - Vertex above lateral ocelli equals half an ocellar diameter or slightly more - Scutum only weakly tessellate, shiny in half or more - Propodeal triangle reticulations absent or limited to extreme base - Depressed area of tergum 2 without punctures (1)
 A. NIDA - Abdomen always black - Vertex above lateral ocelli equals half an ocellar diameter or less - Scutum dulled except in small median area - Propodeal triangle reticulations extend one-third to two-thirds of length from base - Depressed area of tergum 2 with punctures at base, punctures along apex present or absent (1)
Z - A. apacheorum, A. chromotricha, A. scutellinitens - Species in subgenus Cnemidandrena with PALE facial foveal hairs, NARROW tergal apical hairs bands AND hairs on tergum 5 DARKER than on tergum 4
 Not one of these (517)
 A. APACHEORUM - Body length 9.5-11.5 mm - Clypeus SHORT, extending below lower level of compound eyes by about one-third its length - Clypeus punctured throughout although more sparsely in apical half, impunctate midline absent or narrow, surface smooth and shiny in apical half, dulled elsewhere- Scutellum dulled throughout although somewhat shinier in anterior half (1)
 A. CHROMOTRICHA - Body length 7.5-10 mm - Clypeus INTERMEDIATE in length, extending below lower level of compound eyes by about half its length - Clypeus with BROAD impunctate midline, surface smooth and shiny in apical half or more, dulled elsewhere - Scutellum dulled throughout although somewhat shinier in anterior half (1)
 A. SCUTELLINITENS - Body length 7.5-9 mm - Clypeus LONG, extending below lower level of compound eyes by distinctly more than half its own length - Clypeus punctures distinctly sparser medially forming irregular impunctate midline, surface smooth and shiny except along periphery - Scutellum with anterior two-thirds smooth and shiny (1)
Z - A. arabis vs A. geranii
 All the other Andrena species (518)
 A. ARABIS - Integument the typical brown - Lateral ocelli approximately one-half an ocelli diameter from the rear edge of the head - Lining the very border of the rim of S2 are prostrate, short, densely packed hairs that hide the surface below (1)
 A. GERANII - Integument with strong clear gun metal blue metallic reflections - Lateral ocelli approximately one ocelli diameter from the rear edge of the head - There are only a few scattered hairs along the very border of the rim of S2, both species have a set of tall upright hairs set a short distance back from the edge of the rim (1)
Z - A. ardis vs A. neomexicana
 All the other Andrena species (518)
 A. ARDIS - Body longer than 9.5 mm - Vertex above lateral ocelli equals more than 1 ocellar diameter - Facial fovea separated from lateral ocellus by about 1 ocellar diameter (1)
 A. NEOMEXICANA - Body shorter than 9.5 mm - Vertex above lateral ocelli equals about 1 ocellar diameter - Facial fovea separated from lateral ocellus by half an ocellar diameter (1)
Z - A. asteris and A. placata vs A. duplicata
 All the other Andrena species (517)
 A. asteris and A. placata - Mesepisturnum unpitted - Scopal hairs so dense as to completely hide the tibial integument from view - S2-4 in addition to the long hairs along the rim, with short but clearly visible hairs throughout the segment (2)
 A. duplicata - Mesepisturnum with distinct pits - Integument clearly visible beneath the scopal hairs on hind tibia - Hairs on S2-4 almost entirely restricted to scattered long hairs along the rim - In comparison, clypeus somewhat flattened in the center, and unpitted center line of clypeus wider (1)
Z - A. asteris, A. asteroides, A. braccata, A. fulvipennis, A. placata, A. simplex
 All the other Andrena species (514)
 A. PLACATA or A. SIMPLEX - Body length usually 9-10 mm - Malar area between 1-2 times as broad as eye rim - Vertex above lateral ocellus equals 1 ocellar diameter, slightly more or slightly less - Terga 2-3 with apical hair bands usually complete, sometimes interrupted or weak medially on tergum 2 - These two species are distinguished in another character - Hair always on the gray to white end of the spectrum never yellowish (2)
 A. ASTERIS - Body length usually 12-14 mm - Malar area usually 1-2 times as wide as eye rim or - Vertex above lateral ocelli equals 1.25-1.5 ocellar diameters - Propodeal triangle with coarse sculpturing usually restricted to basal third - Tergum 2 punctures absent or obscure and difficult to see - Terga 2-3 with apical hair bands complete to interrupted medially, only moderately dense - Hair in specimens not faded in the sun with a warm yellowish cast (1)
 A. ASTEROIDES - Body length usually 10-11 mm - Malar area rarely wider than eye rim - Vertex above lateral ocelli equals 1 ocellar diameter or only slightly more - Propodeal triangle with coarse sculpturing extending half or more of triangle midline - Tergum 2 punctures weak but visible - Terga 2-3 with apical hair bands interrupted or complete but weak medially, only moderately dense (1)
 A. BRACCATA - UNIQUE in this group for labral process emarginate to shallowly emarginate, rarely entire, never bidentate AND tergum 5 with long apical hairs pale yellow to golden-orange, not brown - Body length usually 10.5-14 mm - Malar area between 1-2 times as broad as eye rim - Vertex above lateral ocellus usually equals 1.5-2 ocellar diameters - Tergum 2 punctures obscured by strong tessellations - Tergum 2 with apical hair band broadly interrupted, tergum 3 with apical hair band narrowly interrupted or weak medially (1)
 A. FULVIPENNIS - UNIQUE in this group for wings deeply infumate, obviously dark to naked eye AND tarsal claws of hind legs smaller than those of middle legs - Body usually 9-11 mm in length - Malar area rarely wider than eye rim - Vertex above lateral ocellus equals 1 ocellar diameter, slightly more or slightly less - Tergum 2 without punctures, surface dull - Terga 2-3 with apical hair bands complete or very narrowly interrupted, narrow, dense (1)
Z - A. aurihirta, A. bendensis, A. citrinihirta, A. pachucensis, A. ramaleyi, A. sulcata - Species in subgenus Cnemidandrena with WIDE tergal apical hair bands AND hairs on tergum 5 PALE like those on tergum 4 AND scutum smooth and shiny at least in part
 Not one of these (514)
 A. AURIHIRTA - Body length 8.5-11.5 mm - Clypeus punctured throughout except small apicomedial impunctate area occupying less than half of clypeus length - Wings with a distinct dark apical spot visible without magnification - Propodeal triangle with longitudinal median depression (1)
 A. BENDENSIS - Body length 6.5-8.0 mm - Antennae reddish-brown below - Scutum smooth and shiny in small median area where punctures separated by about 3 puncture widths, surface somewhat dulled elsewhere - Wings slightly and gradually darkened apically, without distinct dark spot (1)
 A. CITRINIHIRTA - Body length 6.5-8.0 mm - Clypeus with punctures absent or extremely sparse in broad median area occupying more than half of clypeus length - Wings with a distinct dark apical spot visible without magnification - Propodeal triangle without longitudinal median depression (1)
 A. PACHUCENSIS - UNIQUE in this group for distribution in central Mexico - Body length 7.5-9.0 mm - Antennae brownish-yellow below - Scutum textured throughout but texturing weak and surface somewhat shiny in small median area wehre punctures separated by 1-3 puncture widths - Wings slightly and gradually darkened apically, without distinct dark spot (1)
 A. RAMALEYI - Body length 6.5-8.5 mm - Antennae bright yellow below - Scutum smooth and shiny except at extreme edges, punctures in anterior half separated by 1-2 puncture widths and almost absent in posterior median area - Wings slightly and gradually darkened apically, without distinct dark spot (1)
 A. SULCATA - UNIQUE in this group for terga 2-4 with distinct transverse depression posterior to gradulus - Body length 7.0-9.5 mm - Clypeus punctured throughout except small apicomedial impunctate area occupying less than half of clypeus length - Wings with a distinct dark apical spot visible without magnification - Propodeal triangle with longitudinal median depression (1)
Z - A. banksi vs A. dimorpha
 All the other Andrena species (517)
 A. DIMORPHA - First flagellomere as long as or shorter than second - Clypeus surface partially obscured by long, dense, plumose hairs - Tibial scopal hairs at least weakly branched throughout - Tergal apical hair bands of moderate width, pale yellow (1)
Z - A. barbara, A. dunningi, A. macra, A. pruni, A. sayi - Species in subgenus Melandrena with trochanteral flocculus complete and scopal hairs pale at least in part
 All the other Andrena species (515)
 A. BARBARA - Punctures on basal area of T2 distinct and crowded, separated by FAR less than 1 puncture width AND apical depressed area punctures sparse to absent - Width of upper portion of fovea 1.5X or less than that of the lower portion - Body length usually 11-14 mm - Labral process trapezoidal with straight sides, apical margin entire to slightly emarginate - Terga without apical hair bands - Terga occasionally with very weak metallic blue sheen (1)
 A. DUNNINGI - UNIQUE in this group for having tibial scopal hairs below basitibial plate washed with black or dark brown, some populations with almost entirely dark hairs - Punctures on basal area of T2 dense, but shallow and usually obscured by the surrounding matrix of heavy tessilations making them difficult to see except at certain angles, apical depressed area with punctures sparse to absent - Width of upper portion of fovea 1.5 - 2X or more than that of the lower portion - Body length usually 10-13 mm - Labral process large, semicircular, apical margin entire - Terga without apical hair bands (1)
 A. MACRA - UNIQUE in this group for having a noticable pronotal humeral angle with a weak ridge extending down from humeral angle - T2 with basal area punctures distinct and crowded, separated by far less than 1 puncture width, punctures in apical depressed area similarly dense - Width of upper portion of fovea 2X or more than that of the lower portion - Body length usually 11-12 mm - Labral process trapezoidal with straight sides, apical margin clearly emarginate to weakly emarginate - Terga 2-3 with weak apical hair bands broadly interrupted medially, present only laterally - Inner hind tibial spur distinctly kinked or bent in its outer third - A. macra is sometimes placed in subgenus Leucandrena (1)
 A. PRUNI - UNIQUE in this group for having facial fovea separated from inner eye margin by width of antennal pedicel or more, usually much more, the distance between the fovea and eye much wider in the center than the ends of the fovea, A. barabara has a gap that often reaches pedicel width but never more and the width is relatively uniform along the length of the fovea - Punctures on basal area of T2 distinct and crowded, separated by less than 1 puncture width to about 1 and apical depressed area punctures sparse to absent - Width of upper portion of fovea 1.5X or less than that of the lower portion - Body length usually 8-12.5 mm - Labral process large, semicircular, apical margin entire - Terga without apical hair bands (1)
 A. SAYI - T2 with punctures distinct, separated by a bit less than 1 to 1.5 the puncture width across the base of the segment, the depressed apical rim is about the sam puncture density or a bit less - Width of upper portion of fovea 1.5X -2X that of the lower portion - Body length usually 12-14mm - Labral process, large, trapezoidal, apical margin entire - Terga 2-3 with weak apical hair bands broadly interrupted medially, present only laterally (1)
Z - A. barbilabris vs A. illinoiensis
 All the other Andrena species (516)
 A. BARBILABRIS - Labral process as long as wide or longer, strap-like - Abdomen surface shiny, fine lines on surface not obvious and punctures clearly visible - Body length usually 9-12 mm (1)
 A. ILLINOIENSIS - Labrum clearly wider than long - Abdomen surface dulled, highly tessellate as if covered by a fine reptilian skin, punctures not clearly visible - Body length usually 7-9 mm (1)
Z - A. barbilabris vs others
 OTHERS - Labral process wider at base than long (516)
 A. BARBILABRIS - Labral process as long as wide or longer, strap-like (2)
Z - A. bisalicis, A. w-scripta, A. ziziaeformis
 All the other Andrena species (515)
 A. BISALICIS - Body length usually 8-10 mm - Labral process trapezoidal, about twice as broad as long, apical margin entire or slightly emarginate - Vein r longer than 3 vein lengths (1)
 A. W-SCRIPTA - Body length usually 8-11 mm - Labral process with apical margin bidentate - Vein r longer than 3 vein lengths (1)
 A. ZIZIAEFORMIS - Body length usually 7-8 mm - Labral process rectangular, about 3 times as wide as long, apical margin entire or slightly emarginate - Vein r 2-3 vein widths in length (1)
Z - A. bocensis, A. canadensis, A. grindeliae, A. jennei, A. latinensis, A. mentzeliae, A. nubecula, A. rodilla, A. xanthigera - Species in subgenus Cnemidandrena with NARROW tergal apical hair bands AND hairs on tergum 5 PALE like those on tergum 4
 Not one of these (511)
 A. BOCENSIS - Body length 6.0-7.5 mm - Scutum surface SMOOTH and shiny at least in part, punctures separated mostly by 1-3 puncture widths - Tergum 1 without apical hair band except at extreme sides (1)
 A. CANADENSIS - Body length 6.5-8.5 mm - Scutum surface SMOOTH and shiny at least in part, punctures separated by mostly more than 3 puncture widths - Tergum 1 without apical hair band except at extreme sides (1)
 A. GRINDELIAE - Body length 8.5-10.0 mm - Scutum surface SMOOTH and shiny at least in part, punctures separated mostly by 1-3 puncture widths - Tergum 1 with complete apical hair band but not dense nor obscuring surface (1)
 A. JENNEI - Body length 8-10 mm - Known only from a single male from North Yakima, Washington (1)
 A. LATINENSIS - Body length 7.5-9.0 mm - Scutum surface textured throughout, dull, punctures barely visible but separated by 1-3 puncture widths - Tergum 1 with complete apical hair band but not dense nor obscuring surface (1)
 A. MENTZELIAE - Body length 10.0-11.5 mm - Scutum surface textured throughout, dull, punctures barely visible and irregularly spaced - Tergum 1 with complete apical hair band but not dense nor obscuring surface (1)
 A. NUBECULA - Body length 6.5-8.5 mm - Scutum surface textured throughout, dull, punctures separated mostly by 4 or more puncture widths - Tergum 1 without apical hair band except at extreme sides (1)
 A. RODILLA - Body length 7.0-8.5 mm - Scutum surface textured throughout, dull, punctures barely visible but separated by 1-2 puncture widths - Tergum 1 with complete apical hair band but not dense nor obscuring surface (1)
 A. XANTHIGERA - Body length 6.0-8.0 mm - Scutum surface SMOOTH and shiny at least in part, punctures separated mostly by more than 3 puncture widths - Tergum 1 with complete apical hair band but not dense nor obscuring surface (1)
Z - A. brevicornis vs A. transnigra
 None of these apply (518)
 A. BREVICORNIS - Tergum 2 punctures separated mostly by 1 puncture width - Labrum below process without sulcus or longitudinal ridge along midline (1)
 A. TRANSNIGRA - Tergum 2 punctures separated mostly by 2 or more puncture widths - Labrum below process with a depressed longidutinal sulcus bisected by a raised longitudinal ridge at midline (1)
Z - A. brevipalpis vs A. phaceliae
 All the other Andrena species (516)
 A. BREVIPALPIS - Terga 2-3 with apical hair bands narrowly to broadly interrupted, where present usually dense enough to largely obscure surface underneath -Terga without hairs medially or with very short hairs scattered throughout, hairs much shorter than hairs in apical band (1)
 A. PHACELIAE - Terga 2-3 with apical hair bands absent or broadly interrupted medially, extremely weak, surface clearly visible underneath - Terga with long hairs scattered throughout, hairs medially about as long as hairs on apical margins (1)
Z - A. canadensis, A. nubecula, A. robervalensis
 All the other Andrena species (516)
 A. CANADENSIS - Body length usually 7.5-9 mm - Facial fovea with pale hairs - Wings pale- Scutellum surface shiny in half or more of length, tessellation absent or weak except around edges (1)
 A. NUBECULA - Body length usually 7-8.5 mm - Facial fovea with pale hairs - Wings darkened apically and in marginal cell - Scutum surface dulled by tessellation, shiny area absent or occupies less than one-fourth of length (1)
Z - A. candida, A. illustris, A. lauta, A. phaceliae, A. trivialis - Species in subgenus Thysandrena with integument with weak metallic reflections
 Not one of these (515)
 A. CANDIDA - Labrum below process with WEAK median longitudinal ridge - Tergum 2 surface with very fine transverse lines - Tergum 3 with apical hair band distinct, complete or narrowly interrupted (1)
 A. ILLUSTRIS - UNIQUE in this group for scutum and scutellum smooth and shiny except at extreme peripheries (1)
 A. LAUTA - Labrum with WEAK median longitudinal ridge - Tergum 2 surface shagreened like sharkskin at base and at apex smooth with fine lines forming small squares or hexagons - Tergum 3 with apical hair band distinct, narrow interrupted at middle (1)
 A. PHACELIAE - Labrum without median longitudinal ridge - (1)
 A. TRIVIALIS - Labrum without median longitudinal ridge - (1)
Z - A. carlini, A. dunningi, A. regularis - Species in subgenus Melandrena with trochanteral flocculus complete and scopal hairs dark
 All the other Andrena species (515)
 A. CARLINI - Scopal hairs uniformly dark brown to black throughout - Clypeus with clear, broad, shiny unpunctured midline, punctures deep, dense and clear - Hairs on gena always dark brown or black - Pygidial plate U-shaped with broadly rounded apex - Lateral ocelli clearly set about 2 or more diameters back from vertex (1)
 A. DUNNINGI - Scopal hairs even in dark individuals at least slightly paler apically - Clypeus with clear, broad impunctate midline, punctures deep and clear - Hairs on gena all pale - Pygidial plate U-shaped with broadly rounded apex - Lateral ocelli set about 1.5 diameters back from vertex (1)
 A. REGULARIS - Scopal hairs dark brown to black, but with mostly pair hairs on femur - Head, clypeus, in comparison, dull, weakly pitted throughout, without unpitte midline or with unpitted line very obscure - Head, Gena, hairs on gena vary from partially dark brown or black to completely pale - Abdomen, pygidial plate V-shaped with narrowly rounded apex - Lateral ocelli set about 2 diameters back from vertex (1)
Z - A. carolina, A. mandibularis, A. rufosignata, A. thaspii
 All the other Andrena species (514)
 A. CAROLINA - Facial quadrangle distinctly LONGER than wide - Malar area relatively long, about one-fourth or more as long as broad - Labral process emarginate to bidentate - Mandibles LONG, outer mandible when closed clearly exceeds free apical margin of clypeus unless excessively worn - Mandible without basal tooth - Facial fovea with hairs usually pale yellow throughout (1)
 A. MANDIBULARIS - Facial quadrangle as broad as long or slightly broader - Malar area moderate, one-fourth as long as broad or slightly less - Labral process entire - Mandible with small tooth at base near inferior articulation, this tooth may be absent and almost always difficult to spot (1)
 A. RUFOSIGNATA - Facial quadrangle as broad as long or slightly longer - Malar area long, more than one-fourth as long as broad - Labral process emarginate to bidentate - Outer mandible when closed USUALLY does not extend beyond free apical margin of clypeus - Mandible with or without small tooth at base near inferior articulation - Facial fovea with hairs usually DARK brown to black in upper half or more - LONG BLACK HAIRS usually present along the inner margin of the eye and behind the eye where the gena curves around to towards the vertex (1)
 A. THASPII - Facial quadrangle as broad as long or slightly broader - Malar area moderate, one-fourth as long as broad or slightly less - Labral process BIDENTATE- Facial hair can vary from all white to some significant amounts of black, mostly pale in the East and black in the West - Mandible without basal tooth (1)
Z - A. ceanothi, A. cupreotincta, A. forbesii, A. heraclei, A. quintiliformis, A. quintilis, A. salicifloris, A. spiraeana, A. virginiana - Species in subgenus Trachandrena with broadest portion of fovea at least 3 times as wide as narrowest AND widest gap between fovea and eye narrower than scape apex
 All the other Andrena species (513)
 A. CEANOTHI - Face below ocelli as shiny as parocular area or slightly duller, without longitudinal rugulae or rugulae weak, with large punctures separated mostly by 0.5 puncture widths or less - Vertex above lateral ocelli equals about 1.5 ocellar diameters - Scutum hairs normal, long, erect, usually slender - Propodeal sculpturing outside triangle distinctly finer than inside triangle - Punctures along dorsal midline of tergum 1 separated by less than half a puncture width, sometimes touching - Depressed apical area of tergum 2 occupies two-thirds or slightly less of tergum midline - Very end of facial fovea extremely narrow almost just a slot, the similar A. forbesii is wider in comparison (1)
 A. FORBESII - Face below ocelli duller than parocular area, with weak rugulae longitudinal or lacking, with punctures separated mostly by 0.5 puncture widths or less - Vertex above lateral ocelli equals 1.5 ocellar diameters or slightly less - Scutum hairs normal, long, erect, usually slender - Propodeal sculpturing outside triangle distinctly finer than inside triangle - Punctures along dorsal midline of tergum 1 separated by less than half a puncture width, sometimes touching - Depressed apical area of tergum 2 occupies about half of tergum midline (1)
 A. HERACLEI - Face below ocelli as shiny as parocular area, smooth, without rugulae, with small punctures separated mostly by 1 puncture width or slightly more - Vertex above lateral ocelli equals about 1.5 ocellar diameters - Scutum hairs normal, long, erect, usually slender - Propodeal sculpturing outside triangle distinctly finer than inside triangle - Punctures along dorsal midline of tergum 1 separated by 1 puncture or less, occasionally very slightly more - Depressed apical area of tergum 2 occupies two-thirds to three-fourths of tergum midline (1)
 A. QUINTILIS - Face below ocelli duller than parocular area, without longitudinal rugulae or rugulae weak, with punctures separated mostly by 0.5 puncture widths or less - Vertex above lateral ocelli equals nearly two ocellar diameters - Scutum hairs short, thick, appressed, scale-like - Propodeal sculpturing outside triangle about as coarse as inside triangle so that the two are not clearly differentiated - Punctures along dorsal midline of tergum 1 separated by less than half a puncture width, sometimes touching - Depressed apical area of tergum 2 occupies about half of tergum midline (1)
 A. SPIRAEANA - Face below ocelli as shiny as parocular area, smooth, without rugulae, with small punctures separated mostly by 1 puncture width or slightly more - Vertex above lateral ocelli equals about 1.5 ocellar diameters - Scutum hairs normal, long, erect, usually slender - Propodeal sculpturing outside triangle distinctly finer than inside triangle - Punctures along dorsal midline of tergum 1 separated by 1 to several puncture widths, usually with several areas where spacing is clearly more than 1 puncture width - Depressed apical area of tergum 2 occupies about two-thirds to three-quarters of tergum midline (1)
 A. VIRGINIANA - Face above antennal sockets without longitudinal rugulae, surface shiny with coarse, crowded punctures - Scutum punctures between parapsidal lines separated irregularly by half to several puncture widths, often quite sparse - Propodeum with triangle without clear ridged sides, boundaries relatively indistinct, adjacent areas often sculptured nearly as coarsely as triangle - Hind tibia dark - Tergum 1 punctures on dorsal midline uniformly dense throughout or slightly sparser basally - Tergum 2 depressed apical area occupying one-half to two-thirds of midline - Told from the very similar A. rehni by the relatively coarse punctures on tergum 2 being spaced less than 1 puncture width apart (1)
Z - A. chromotricha vs A. banksi
 All the other Andrena species (518)
 A. banksi - Clypeus dulled uniformly throughout by microscopic lines and not reflecting light- In direct comparison the pygidial plate is wider and larger (1)
 A. chromotricha - Clypeus dulled by microscopic lines only along the far sides and at the base, the central area without these lines and clearly glossy and reflecting light - In comparison the pygidial plate narrower and smaller (1)
Z - A. chromotricha vs. A. macoupinensis
 All the other Andrena species (518)
 A. CHROMOTRICHA - In comparison, the hair band along the tergites is denser and less of the tegument below is visible, the hairs in the hair band very clearly longer than the few hairs present throughout the rest of the segment - The length of flagellar segment 1 about the same or slightly less than F2 and F3 combined - Integument of the hind tibiae with the usual brown cast (1)
 A. MACOUPINENSIS - In comparison, the hair band along the tergites is looser and less of the tegument below is visible, the hairs in the hair band very nearly long as the hairs present throughout the rest of the segment - The length of flagellar segment 1 is very clearly longer than F2 and F3 combined - Integument of the hind tibiae usually with an orangish cast (1)
Z - A. clarkella vs others
 OTHERS - Characters not as in A. clarkella (517)
 A. CLARKELLA- Scopal hairs and apex of tibia orange, contrasting with dark black abdominal hairs and surface (1)
Z - A. colletina, A. columbiana, A. hirticincta, A. runcinatae, A. scutellinitens, A. specularia, A. surda - Species in subgenus Cnemidandrena with WIDE tergal apical hair bands AND hairs on tergum 5 DARKER than on tergum 4
 Not one of these (513)
 A. COLLETINA - Body length 11.5-14.5 mm - Clypeus INTERMEDIATE in length, extending below lower level of compound eyes by about half its length - Facial fovea with PALE hairs throughout - Scutellum dulled throughout - Tibial scopal hairs pale to dark - Terga 3 and 4 with very short, erect, DARK hairs on sides (1)
 A. COLUMBIANA - Body length 7.5-10.0 mm - Clypeus INTERMEDIATE in length, extending below lower level of compound eyes by about half its length - Facial fovea with PALE hairs throughout - Tibial scopal hairs PALE throughout - Wings only slightly darkened apically - Terga 3 and 4 with only PALE hairs - (1)
 A. HIRTICINCTA - Body length 11.0-13.5 mm - Clypeus SHORT, extending below lower level of compound eyes by about one-third its length - Facial fovea with PALE hairs throughout - Tibial scopal hairs DARK in basal half or more - Terga 3 and 4 with only PALE hairs (1)
 A. RUNCINATAE - Body length 8.5-11.5 mm - Clypeus SHORT, extending below lower level of compound eyes by about one-third its length - Facial fovea with DARK hairs throughout - Scutum with at least some dark hairs - Terga 3 and 4 with very short, erect, DARK hairs on sides (1)
 A. SCUTELLINITENS - Body length 7.5-9.0 mm - Clypeus LONG, extending below lower level of compound eyes by distinctly more than half its own length - Facial fovea with PALE hairs throughout - Scutellum with anterior two-thirds smooth and shiny - Tibial scopal hairs PALE throughout or sometimes dark in basal fourth - Terga 3 and 4 with very short, erect, DARK hairs on sides (1)
 A. SPECULARIA - Body length 8.5-10.0 mm - Clypeus INTERMEDIATE in length, extending below lower level of compound eyes by about half its length - Facial fovea with DARK hairs throughout - Scutum with at least some dark hairs - Terga 3 and 4 with very short, erect, DARK hairs on sides (1)
 A. SURDA - Body length 8.5-11.5 mm - Clypeus SHORT, extending below lower level of compound eyes by about one-third its length - Facial fovea with PALE hairs throughout - Tibial scopal hairs PALE throughout - Wings distinctly darkened apically - Terga 3 and 4 with only PALE hairs (1)
Z - A. commoda, A. confederata, A. dolomellea, A. hilaris, A. illini, A. nivalis, A. obscuripennis - Species in subgenus Melandrena with trochanteral flocculus incomplete and scopal hairs pale at least in part
 All the other Andrena species (511)
 A. COMMODA - Body length usually 9-13 mm - Labral process trapezoidal, apex entire to slightly emarginate - Hind tibia reddish-brown to bright orange, occasionally dark - Tergum 2 with punctures weak but apparent, separated by from under 1-3 puncture widths throughout - Tergum 5 with hairs golden-yellow to bright orange - Pygidial plate apex narrowly rounded (1)
 A. CONFEDERATA - UNIQUE in this group for having vertex above lateral ocelli equals 1 ocellar diameter or less, the others much greater - Body length usually 10-13 mm - Labral process broad and trapezoidal, apex usually weakly emarginate, rarely entire - Hind tibia dark - Tergum 2 virtually impunctate, punctures extremely weak and separated by more than 2 puncture widths - Tergum 5 with hairs light brown to blackish - Pygidial plate usually with raised internal triangle, plate apex broadly rounded (1)
 A. DOLOMELLEA - UNIQUE in this group for having clypeus, scutellum and metanotum and abdomen with reddish or orange integument - Body length usually 12-15 mm - Wing membranes deeply infumate, dark brown throughout (1)
 A. HILARIS - Body length usually 13-15 mm - Labral process trapezoidal, truncate, apex entire to weakly emarginate - Hind tibia dark - Tergum 2 with punctures weak but apparent, separated by 1-2 puncture widths basally, becomes sparser towards the edge of the depressed apical area and then increases again in the depressed area - Tergum 5 with hairs brown to blackish to golden brown - Pygidial plate apex truncate or broadly rounded - In comparison to A. illini, has dense apical hair bands on the far sides of T2 and T3, these often extending well towards the center of the rim and are thick enough to hide the rim (1)
 A. ILLINI - Body length usually 13-15 mm - Labral process semicircular to roughly truncate, apex entire - Hind tibia dark - Tergum 2 with punctures weak but apparent, separated by 1-3 puncture throughout the segment - Tergum 5 with hairs golden-yellow to bright orange - Pygidial plate apex broadly rounded or weakly emarginate (1)
 A. NIVALIS - UNIQUE in this group for having tibial scopal hairs below basitibial plate washed with black or dark brown - Body length usually 12-15 mm - Labral process trapezoidal, apex entire to weakly emarginate - Hind tibia dark - Tergum 2 with punctures quite weak and shallow but apparent upon close inspection, separated by 1-3 puncture widths throughout - Tergum 5 with hairs brown to blackish - Pygidial plate apex narrowly rounded or truncate, almost pointed (1)
 A. OBSCURIPENNIS - UNIQUE in this group for COMBINATION of dark integument except hind tibia bright red to orange AND wing membranes deeply infumate, dark brown throughout - Body length usually 13-15 mm - Labral process trapezoidal, apex weakly emarginate - Tergum 2 with punctures obvious and dense, less than 1 puncture width apart throughout - Pygidial plate apex broadly rounded or weakly truncate (1)
Z - A. cornelli, A. nubecula, A. tridens
 All the other Andrena species (515)
 A. CORNELLI - Terga 2-3 with apical hair bands absent or broadly interrupted and weak, integument clearly visible beneath hairs - Tibial scopa with long, unusually sparse hairs not hiding surface of tibia - Femur hairs simple, unbranched (1)
 A. NUBECULA - Terga 2-3 with apical hair bands complete, dense, hiding integument below (1)
 A. TRIDENS - Terga 2-3 with apical hair bands absent or broadly interrupted and weak, integument clearly visible beneath hairs - Tibial scopa normal, surface of tibia partially obscured by hairs - Femur with some hairs weakly branched near tips (1)
Z - A. costillensis, A. luteihirta, A. mentzeliae, A. rodilla - Species in subgenus Cnemidandrena with WIDE tergal apical hair bands AND hairs on tergum 5 PALE like those on tergum 4 AND scutum dulled by texturing throughout, without smooth and shiny area
 Not one of these (516)
 A. COSTILLENSIS - Body length 7.0-10.0 mm - Clypeus dulled by dense texturing in upper half, less so medially and apically - Malar space narrow - Wings slightly darker apically but without distinct dark apical spot - Terga 2-4 with apical hair bands covering one-third to half of tergal length (1)
 A. LUTEIHIRTA - UNIQUE in this group for wings with distinct dark apical spot visible without magnification - Body length 8.0-11.0 mm - Clypeus dulled by dense texturing in upper half, less so medially and apically - Malar space narrow - Terga 2-4 with apical hair bands covering more than half of tergal length (1)
 A. MENTZELIAE - UNIQUE in this group for clypeus smooth and shiny except at extreme edges, punctures almost completely absent in median third, hairs restricted to edges - Body length 10.0-11.5 mm - Terga 2-4 with apical hair bands covering only about one-third of tergal length (1)
 A. RODILLA - UNIQUE in this group for malar space moderately long, about one-fifth as long as broad - Body length 7.0-8.5 mm - Clypeus dulled by dense texturing in upper half, less so medially and apically - Wings slightly darker apically but without distinct dark apical spot - Terga 2-4 with apical hair bands covering only about one-third of tergal length (1)
Z - A. cragini, A. melanochroa, A. ziziaeformis
 All the other Andrena species (515)
 A. CRAGINI - Body length usually 9-11 mm - Vein r about 3-4 vein widths in length - Tergum 2 with distinct punctures - Labral process trapezoidal with straight sides and truncate apex, apical margin entire to weakly emarginate (1)
 A. MELANOCHROA - Body length usually 5-7 mm - Vein r 1-3 vein widths in length- Tergum 2 without punctures - Labral process semicircular, rounded from side to side, apical margin entire (1)
 A. ZIZIAEFORMIS - Body length usually 5-8 mm - Vein r usually about 3-4 vein widths in length, occasionally less - Tergum 2 with weak punctures - Labral process semicircular, rounded from side to side, apical margin entire to weakly emarginate (1)
Z - A. cressonii - subspecies
 All the other Andrena species (515)
 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 - Eastern and Great Plains distribution (1)
 A. CRESSONII INFASCIATA - Legs dark - Terga with apical hair bands absent or present only on lateral edges - Western and southwestern distribution (1)
 A. CRESSONII KANSENSIS - Hind leg tibia and tarsi bright orange or red - Tergum 2 with apical hair band narrowly interrupted, tergum 3 hair band complete or extremely narrowly interrupted - Great Plains and southwestern distribution (1)
Z - A. cressonii vs A. macra - Similar in that both have densely pitted abdomens and weak to strong pronotal humeral angles
 None of these apply (518)
 A. CRESSONII - Top of fovea only slightly wider than the bottom - Dorsal surface of the propodeum clearly longitudinally longer than metanotum, nearly as long as scuttelum - Inner hind tibial spur of normal shape not distinctly kinked or bent in its outer third - In comparison slightly smaller (1)
 A. MACRA - Top of fovea about 2X the width of the bottom - Dorsal surface of the propodeum only slightly longitudinally longer than metanotum or about the same size - Inner hind tibial spur distinctly kinked or bent in its outer third - In comparison slightly larger (1)
Z - A. daeckei vs A. kalmiae - Species in subgenus Scrapteropsis with hind femur rounded ventrally, without ridges AND with maxillary palpi short, not or barely exceeding galea when both extended forward
 All the other Andrena species (516)
 A. DAECKEI - Body length usually 7-8 mm - Vertex above lateral ocelli distinctly shorter than one ocellar diameter - Scutum punctures between parapsidal lines separated by 2-5 puncture widths - Tergum 2 with depressed apical areas equal to distinctly more than one-third of median tergal length (1)
 A. KALMIAE - Body length usually 9-10 mm - Vertex above lateral ocelli equal one ocellar diameter or slightly more - Scutum punctures between parapsidal lines separated by 1 puncture width or less - Tergum 2 with depressed apical areas equal to one-third of median tergal length (1)
Z - A. distans vs A. erigeniae
 All the other Andrena species (516)
 A. DISTANS - Galea narrow, shiny, pointed - Vertex above lateral ocelli equals one ocellar diameter or slightly more - Pronotal ridge distinct, with a clear ridge with a raised line running down at least the lower two-thirds of that ridge and the region between the ridge and the pronotal lobe shiny and much less covered by microscopic lines than the ridge is (1)
 A. ERIGENIAE - Galea broad, dulled, apex rounded - Vertex above lateral ocelli equals less than one ocellar diameter - Pronotal ridge weak, pronotum dulled throughout by microscopic lines (1)
Z - A. dunningi vs A. erythronii
 All the other Andrena species (516)
 A. DUNNINGI - Facial fovea extends to level of upper margin of clypeus or below - Pronotum without humeral angle or ridge - Scutellum and metanotum partially obscured by dense hairs, hairs golden-orange to bright orange - Terga without pale apical hair bands (1)
 A. ERYTHRONII - Facial fovea extends to level of antennal socket or below, not reaching to level of upper margin of clypeus - Pronotum with weak humeral angle and ridge - Scutellum and metanotum not obscured by hairs, hairs pale yellow to pale yellow-orange - Terga 2-4 with weak, often interrupted, pale apical hair bands (1)
Z - A. erigeniae vs A. miserabilis
 All the other Andrena species (516)
 A. ERIGENIEAE - Entire clypeus covered with hair, surface punctured and dull (1)
 A. MISERABILIS - Clypeus largely impunctate and without hairs, surface smooth and shiny (1)
Z - A. erythrogaster, A. perplexa, A. wilmattae
 All the other Andrena species (516)
 A. ERYTHROGASTER - Body length usually 10-12 mm - Abdomen usually red at least in part, rarely all black - Labrum without distinct longitudinal ridges - Pronotum humeral angle weak to distinct but not depressed posteriorly and not forming ear-shaped lobe - Terga 2-4 moderately dull, punctures minute, invisible except at high magnification, separated by 3 or more puncture widths (1)
 A. PERPLEXA - Body length usually 12-15 mm - Body entirely dark - Labrum with median longitudinal ridge flanked by two shiny, concave depressions - Pronotum humeral angle distinct, depressed posteriorly to form ear-shaped lobe, lower-lateral surface dulled throughout - Terga 2-4 moderately shiny, punctures small but distinct, separated by 1-2 puncture widths (1)
 A. WILMATTAE - Body length usually 10-14 mm - Body entirely dark - Labrum without distinct longitudinal ridge but usually with shiny subapical longitudinal depression - Pronotum humeral angle distinct, narrowly depressed posteriorly to form small ear-shaped lobe, rear-lateral surface shiny - Terga 2-4 moderately shiny, punctures small but distinct, separated by about 1 puncture width (1)
Z - A. erythronii vs A. tridens
 All the other Andrena species (518)
 A. ERYTHRONII - Distance from lateral ocelli to edge of fovea less than the diameter of the ocelli - Corbicula on lateral face of propodeum with a clear line of branched hairs along the anterior edge (1)
 A. TRIDENS - Distance from lateral ocelli to edge of fovea greater than the diameter of the ocelli - Corbicula on lateral face of propodeum with a no branched hairs along the anterior edge or only a very few (1)
Z - A. fenningeri, A. ilicis, A. imitatrix, A. morrisonella, A. rubi - Species in subgenus Scrapteropsis with hind femur rounded ventrally, without ridges AND with maxillary palpi of normal length
 All the other Andrena species (513)
 A. FENNINGERI - UNIQUE in this group for having tergum 2 with punctures on basal area dense, separated by less than one puncture width, and contrasting markedly with depressed apical area where punctures separated by 2 or more puncture widths - Vertex above lateral ocelli equals less than one ocellar diameter - Labral process trapezoidal, apex entire - Terga 2-4 with apical hair bands weak, interrupted and not obscuring tergal surface (1)
 A. ILICIS - Vertex above lateral ocelli variable, equals one, more than one, or less than one ocellar diameter - Labral process trapezoidal, apex emarginate to weakly emarginate - Terga 2-4 with apical hair bands relatively dense to very dense, usually broadly interrupted on tergum 2 and sometimes 3 - Punctures in the center of T2 separated by between 1-3 puncture widths and are about the same density on the depressed rim - Lateral edges of propodeal only vaguely demarcated, no apparent line or carina separates the triangle from the rest of the propodeum, the surface outside of the triangle a bit less coarse than that inside the tirangle, but not greatly so as in A. morrisonella - Some individuals have rear legs with orange tibia and tarsal segments and may superficially resemble A. hippotes (1)
 A. IMITATRIX - UNIQUE in this group for having propodeal corbicula hairs in anterior half mostly or entirely branched - Vertex above lateral ocelli equals one ocellar diameter or less - Labral process trapezoidal, apex entire to weakly emarginate - Terga 2-4 with apical hair bands always interrupted on tergum 2 and usually weak medially on terga 3 and 4, occasionally absent (1)
 A. MORRISONELLA - Vertex above lateral ocelli equals one ocellar diameter or less - Labral process distinctly narrowed apically, apex entire to emarginate - Terga 2-4 with apical hair bands absent or restricted to lateral margins, more than half of tergal width bare - T2 punctures are very dense, much less than 1 puncture diameter apart, pits on the rim slightly less dense - Lateral edges of propodeal triangle crisply demarcated by a raised very straight line, a carina, separting the triangle from the rest of the propodeum, the surface outside of the triangle clearly not as coarsely lined as that inside the triangle (1)
 A. RUBI - UNIQUE in this group for having thoracic dorsum with short, thick, scale-like hairs, densest along margins AND propodeal triangle with coarse texturing not filling dorsal part of triangle - Vertex above lateral ocelli equals one or more ocellar diameters - Labral process distinctly narrowed apically, apex bidentate - Terga 2-4 with apical hair bands dense, complete or narrowly interrupted medially, less than half of tergal width bare (1)
Z - A. flexa, species in subgenus Plastandrena, others
 OTHERS - Hind tibial spur relatively straight or only very slightly curved (510)
 MEMBER of subgenus Plastandrena - Both tibial spurs of rear leg noticeable more curved throughout than spur on middle leg - Fore spur of hind leg usually shorter than hind spur, hind spur broadened and flattened near base and sometimes slightly twisted along length (7)
 A. FLEXA - Hind tibial spur of rear leg distinctly bent at about two-thirds to three-quarters of its length creating an approximately 150 degree angle (1)
Z - A. forbesii, A. hippotes, A. mariae, A. miranda, A. rehni, A. sigmundi, A. virginiana - Species in subgenus Trachandrena with broadest portion of fovea NO MORE THAN 2.5 times as wide as narrowest
 All the other Andrena species (511)
 A. FORBESII - Face below ocelli duller than parocular area, with or without weak longitudinal rugulae, with punctures separated mostly by 0.5 puncture widths or less - Vertex above lateral ocelli equals 1.5 ocellar diameters or slightly less - Scutum hairs normal, long, erect, usually slender - Propodeal sculpturing outside triangle distinctly finer than inside triangle - Punctures along dorsal midline of tergum 1 separated by less than half a puncture width, sometimes touching - Depressed apical area of tergum 2 occupies about half of tergum midline (1)
 A. HIPPOTES - Face above antennal sockets without longitudinal rugulae or these weak, surface dull with small well-spaced punctures - Scutum punctures between parapsidal lines separated by 1-3 puncture widths or more - Propodeum with triangle set off by well marked to only vague ridges or none at all and coarse internal texture, adjacent areas about equally coarsely textured to moderately finer - Hind tibia usually red to orange, rarely dark - Tergum 1 punctures on dorsal midline distinctly sparser basally than apically - Tergum 2 depressed apical area occupying half to about two-thirds of midline (1)
 A. MARIAE - UNIQUE in this group for abdomen usually red at least in part, occasionally all dark - Face above antennal sockets with longitudinal rugulae distinct to weak, surface shiny with small well-spaced punctures - Scutum punctures between parapsidal lines separated regularly by half to 2 puncture widths - Propodeum with triangle set off by weak ridges and coarse internal texture, adjacent areas more finely and densely sculptured - Hind tibia red to orange or dark in dark individuals - Tergum 1 punctures on dorsal midline uniformly dense throughout (1)
 A. MIRANDA - UNIQUE in this group for tergum 2 depressed apical area occupying three-fourths or more of midline - Face above antennal sockets without longitudinal rugulae, surface shiny with coarse, crowded punctures - Scutum punctures between parapsidal lines separated regularly by half to 2 puncture widths - Propodeum with triangle without ridged sides, boundaries indistinct, adjacent areas often sculptured nearly as coarsely as triangle - Hind tibia dark - Tergum 1 punctures on dorsal midline uniformly dense throughout (1)
 A. REHNI - Face above antennal sockets without longitudinal rugulae or these weak, surface dull with small punctures - Scutum punctures between parapsidal lines separated irregularly by half to several puncture widths - Propodeum with triangle without clear ridged sides, boundaries relatively indistinct, adjacent areas often sculptured nearly as coarsely as triangle - Hind tibia dark - Tergum 1 punctures on dorsal midline distinctly sparser basally than apically - Tergum 2 depressed apical area occupying two-thirds to one half of midline - Told from similar A. virginiana by the very small size and sparseness of punctures on the base of tergum 2, these often separated by more than 3 puncture widths (1)
 A. SIGMUNDI - UNIQUE in this group for hind tibial spur of rear leg very gently doubly bent in the outer two-thirds, note this along the axis OPPOSITE that of the main curve of the spur - Face above antennal sockets without longitudinal rugulae, surface shiny but with coarse, raised, crowded punctures - Scutum punctures between parapsidal lines separated by 1 puncture width or less - Propodeum with triangle set off by ridges and coarse internal texture, adjacent areas more finely and densely sculptured - Hind tibia dark - Tergum 1 punctures on dorsal midline uniformly dense throughout or slightly sparser basally (1)
 A. VIRGINIANA - Face above antennal sockets without longitudinal rugulae, surface shiny with coarse, crowded punctures - Scutum punctures between parapsidal lines separated irregularly by half to several puncture widths, often quite sparse - Propodeum with triangle without clear ridged sides, boundaries relatively indistinct, adjacent areas often sculptured nearly as coarsely as triangle - Hind tibia dark - Tergum 1 punctures on dorsal midline uniformly dense throughout or slightly sparser basally - Tergum 2 depressed apical area occupying one-half to two-thirds of midline - Told from the very similar A. rehni by the relatively coarse punctures on tergum 2 being spaced less than 1 puncture width apart (1)
Z - A. fragilis vs A. platyparia
 All the other Andrena species (516)
 A. FRAGILIS - Labral process rectangular, with parallel sides - Tibial scopal hairs entirely simple - Tergum 2 with punctures on depressed apical area distinctly sparser than basally (1)
 A. PLATYPARIA - Labral process trapezoidal, apex narrower than base - Tibial scopal hairs branched at least along margins - Tergum 2 with punctures on depressed apical area as dense or only slightly sparser than basally (1)
Z - A. gardineri vs A. krigiana
 All the other Andrena species (516)
 A. GARDINERI - Body length usually 9-11 mm - Labral process with apical margin distinctly emarginate to bidentate, with a V- shaped indentation - Propodeal corbicula with long internal hairs scattered in upper two-thirds or more - Propodeal triangle with coarse texture restricted to extreme base or sometimes slightly further along midline, never more than half of length nor half of width rugulose - Tergum 1 with apical hair band present, distinct, narrowly to broadly interrupted medially - Terga 2-4 with apical hair bands usually complete, dense and broad, obscuring translucent portion of apical margin except where interrupted medially (1)
 A. KRIGIANA - Body length usually 8-9 mm - Labral process with apical margin entire or very weakly emarginate - Propodeal corbicula with long internal hairs restricted to upper third, although shorter hairs scattered throughout - Propodeal triangle with coarse texture filling basal half or more - Tergum 1 with apical hair band absent - Terga 2-4 with apical hair bands usually interrupted medially, weak and narrow, not obscuring translucent portion of apical margin (1)
Z - A. geranii, A. melanochroa, A. neonana, A. robertsonii
 All the other Andrena species (514)
 A. GERANII - Body length usually 8-11 mm - Thorax and abdomen usually weakly metallic - Vein r 4 or more vein widths in length - Propodeal triangle with coarse texturing rarely occupying more than half of triangle length (1)
 A. MELANOCHROA - Body length usually 5-7 mm - Body dark, not metallic - Vein r 1-3 vein widths in length - Propodeal triangle usually filled with weak irregular rugulae, without median longitudinal line - In comparison to A. neonana the surface structure outside of the propodeal triangle is a uniform field of pebbles very unlike that of the coarse raised surface inside the triangle and the hind tibia is noiticably much wider at the apical end and overall stouter (1)
 A. NEONANA - Body length usually 5-7 mm - Body dark, not metallic - Vein r 1-3 vein widths in length - Propodeal triangle filled with distinct irregular rugulae, with or without a median longitudinal line that extends at least half of triangle length - In comparison to A. melanochroa the surface structure outside of the propodeal triangle is nearly the same texture as that within the triangle and is a mixture of coarse raised mounds and lines additionally, the hind tibia is quiite narrow and relatively thin (1)
 A. ROBERTSONII - Body length usually 8-10 mm - Body dark, not metallic - Vein r 4 or more vein widths in length - Propodeal triangle with coarse texturing usually filling triangle (1)
Z - A. heraclei, A. nuda, A. rugosa, A. spiraeana - Species in subgenus Trachandrena with widest gap between fovea and eye equal to or broader than scape apex
 All the other Andrena species (514)
 A. HERACLEI - Face below ocelli as shiny as parocular area, smooth, without rugulae, with small punctures separated mostly by 1 puncture width or slightly more - Punctures on scutum irregularly spaced, separated by less than 1 to 2 or more puncture widths - Widest gap between eye and fovea distinctly wider than fovea at that point - Punctures along dorsal midline of tergum 1 separated by 1 puncture or less, occasionally very slightly more - Punctures along dorsal midline of tergum 1 separated by 1 puncture or less, rarely very slightly more - Depressed apical area of tergum 2 occupies two-thirds to three-fourths of tergum midline (1)
 A. NUDA - UNIQUE in this group for scutum almost impunctate, punctures extremely sparse, separated by 3 puncture widths or more on average, variable in size AND scutum hairs often absent medially, long and simple when present, hairs along edges extremely short and highly plumose - Face above antennal sockets with distinct rugulae and large punctures (1)
 A. RUGOSA - UNIQUE in this group for punctures on scutum large, coarse, overlapping or separated by at most half a puncture width throughout, punctures giving rise to long, hairs with minute branches apparent at high magnification - Face above antennal sockets with weak to distinct rugulae and with large punctures - Widest gap between eye and fovea distinctly wider than fovea at that point - Depressed apical area of tergum 2 occupies two-thirds or more of tergum midline (1)
 A. SPIRAEANA - UNIQUE in this group for widest gap between eye and fovea scarcely wider than fovea at that point AND punctures along dorsal midline of tergum 1 fine and sparse, usually separated by several puncture widths - Face below ocelli as shiny as parocular area, smooth, without rugulae, with small punctures separated mostly by 1 puncture width or slightly more - Punctures on scutum irregularly spaced, separated by less than 1 to 2 or more puncture widths - Depressed apical area of tergum 2 occupies two-thirds to three-quarters of tergum midline (1)
Z - A. imitatrix, A. mariae, A. mendica, A. morrisonella
 All the other Andrena species (514)
 A. IMITATRIX - Abdomen dark - Tergum 2 with basal area punctures as dense as or sparser than on depressed apical area - Depressed apical area of tergum 2 occupies one third of tergal length - Vertex above lateral ocelli equals one ocellar diameter or slightly less - Labral process entire, truncate or slightly emarginate - Propodeal corbicula with branched internal hairs in anterior half (1)
 A. MARIAE - Abdomen usually red or dark red, occasionally dark - Tergum 2 with basal area punctures denser than on apical depressed area - Depressed apical area of tergum 2 occupies one half or more of tergal length - Vertex above lateral ocelli equals about one ocellar diameter - Labral process entire, truncate or slightly emarginate - Propodeal corbicula with simple internal hairs (1)
 A. MENDICA - Abdomen dark - Tergum 2 with basal area punctures denser than on apical depressed area - Depressed apical area of tergum 2 occupies one third of tergal length - Vertex above lateral ocelli equals about one ocellar diameter or slightly more - Labral process entire, rounded - Propodeal corbicula with simple internal hairs (1)
 A. MORRISONELLA - Abdomen dark - Tergum 2 with basal area punctures denser than on apical depressed area - Depressed apical area of tergum 2 occupies one third of tergal length - Vertex above lateral ocelli equals about 1 diameter or slightly less - Labral process distinctly narrowed apically, entire to shallowly and narrowly emarginate - Propodeal corbicula with simple internal hairs (1)
Z - A. lamelliterga vs A. ziziae
 All the other Andrena species (516)
 A. LAMELLITERGA - Note, this species is much rare than A. ziaiae - Head, Tongue, Galea acutely and somewhat sharply pointed - Head, Antennae short, reaching back to mid-tegula at most, comparative difference in length between F2 and F9 much less - Abdomen, Tergites, clear hyaline rim of T2-4 broad, nearly as wide as the apical hair bands along the sides of the rim (1)
 A. ZIZIAE - Note, this species is much more common - Head, Tongue, Galea normal, apex about a 45 degree angle - Head, Antennae reach back to rear of tegula or slightly beyond, comparative difference in length between F2 and F9 much greater - Abdomen, Tergites, clear, hyaline rim of T2-4 narrower than apical hair bands (1)
Z - A. lupinorum, A. nivalis, A. vicina - Species in subgenus Melandrena with trochanteral flocculus incomplete and scopal hairs dark
 All the other Andrena species (515)
 A. LUPINORUM - Scopal hairs black - Mesepisternum hairs black - Vertex above lateral ocelli equals almost exactly 2 ocellar diameters - While very subtle, the portion of the labrum between the rim and the process is divided into a number of small shiny very shallow cells separated by narrow dull lines, the other species usually have this region split into two long cells with one central dividing line (1)
 A. NIVALIS - Scopal hairs usually pale at least in part, although some western specimens can have hairs all black - Mesepisternum hairs usually white, rarely black - Vertex above lateral ocelli equals 2 or more ocellar diameters (1)
 A. VICINA - Scopal hairs black - Mesepisternum hairs pale - Vertex above lateral ocelli equals less than 2 ocellar diameters (1)
Z - A. macoupinensis vs A. rufosignata
 All the other Andrena species (516)
 A. MACOUPINENSIS - Malar area usually about twice as long as eye rim or slightly more or less, not one-fourth as long as wide - Clypeus not elongate, not more than half its median length extending below level of lower margins of compound eyes - Clypeus punctures in direct comparison denser (1)
 A. RUFOSIGNATA - Malar area long, about one-fourth as long as wide - Flagellomeres just about equally dark on top as on bottom - Clypeus elongate, more than half its median length extending below level of lower margins of compound eyes - In direct comparison pitting on clypeus sparse, with a broad impunctate midline (1)
Z - A. macra vs A. wilmattae
 All the other Andrena species (518)
 A. macra - Easily told from A. wilmattae by the dense pattern of pits continueing from the base of T2 and T3 onto the depressed portions of the rims at the same density - In direct comparison smaller (1)
 A. wilmattae - Easily told from A. macra by the dense pattern of pits continueing from the base of T2 and T3 onto the depressed portions of the rims at a dramatically reduced density - In direct comparison larger (1)
Z - A. mariae vs A. miranda - Width of depressed apical area of tergum 2
 All the other Andrena species (516)
 A. MARIAE - Depressed region of tergum 2 occupies about one half of longitudinal length in the center of the segment (1)
 A. MIRANDA - Depressed region of tergum 2 occupies two-thirds or more of the longitudinal length in the center of the segment (1)
Z - A. nigrae vs A. personata
 All the other Andrena species (518)
 A. NIGRAE - Hind tibia less than 1.5x wide at the apex as at the base - Clypeus usually with a clear, unpitted median, longitudinal line - T2-3 usually with weak to absent hair bands along rim - In direct comparison slightly larger (1)
 A. PERSONATA - Hind tibia cuneate, more than 1.5x wide at the apex as at the base - Clypeus without an unpitted line - T2-4 usually with strongly defined hair bands along the apical rim varying from complete to absent in the center - In direct comparison slightly smaller (1)
Z - A. parnassiae, A. peckhami, A. runcinatae, A. specularia - Species in subgenus Cnemidandrena with DARK facial foveal hairs
 Not one of these (516)
 A. PARNASSIAE - UNIQUE in this group for BLACK HAIRS on clypeus, vertex, and thorax - Body length about 8-10 mm - Clypeus SHORT, extending below lower level of compound eyes by about one-third its length - Clypeus surface strongly punctured, with narrow impunctate midline - Scutellum dull - NOTE that we have not seen this species and it may not actually be a Cnemidandrena (1)
 A. PECKHAMI - Body length 7.5-10 mm - Clypeus LONG, extending below lower level of compound eyes by distinctly more than half its own length - Clypeus with BROAD, SLIGHTLY ELEVATED impunctate midline - Scutellum shiny in anterior two-thirds, surface only weakly textured (1)
 A. RUNCINATAE - Body length 8.5-11.5 mm - Clypeus SHORT, extending below lower level of compound eyes by about one-third its length - Clypeus punctured throughout but punctures sparser in apicomedial half, impunctate midline absent or narrow, surface dulled throughout without distinct smooth shiny area - Scutum with at least some dark hairs - Scutellum dulled but somewhat shinier anteriorly where texturing is weak (1)
 A. SPECULARIA - Body length 8.5-10 mm - Clypeus INTERMEDIATE in length, extending below lower level of compound eyes by about half its length - Clypeus surface punctured throughout, dulled throughout without distinct smooth shiny area - Scutum with at least some dark hairs - Scutellum smooth and shiny in anterior two-thirds - (1)
Z - A. persimulata vs A. platyparia
 All the other Andrena (518)
 A. persimulata - Easily identified by the presence of a large projecting knob or large swelling at the bottom of the lateral face of the mesepisturnum about half way between the front and mid legs (1)
 A. platyparia - Not as above (1)
Z - A. personata, A. robertsonii, A. ziziae, A. ziziaeformis
 All the other Andrena species (514)
 A. PERSONATA - Body length usually 5-7 mm - Vein r about 1-2 vein width in length - Tergum 2 without punctures - Tergum 3 with weak apical hair band, scarcely obscures surface, usually narrowly to broadly interrupted, occasionally absent - Fovea only slightly broader at widest point than at level of antenna base (1)
 A. ROBERTSONII - Body length usually 8-10 mm - Vein r 4 or more vein widths in length - Tergum 2 with small punctures visible at high magnification, may be obscured by texturing at lower magnification - Tergum 3 with apical hair band distinct, hiding surface below, broadly interrupted to complete medially (1)
 A. ZIZIAE - Body length usually 5.5-7.5 mm - Vein r about 1-2 vein widths in length - Tergum 2 without punctures - Tergum 3 with weak apical hair band, scarcely obscures surface, usually narrowly to broadly interrupted, occasionally absent - Fovea at widest point more than 1.5 times its width at level of antenna sockets (1)
 A. ZIZIAEFORMIS - Body length usually 6-8 mm - Vein r about 2-3 vein widths in length - Tergum 2 with small punctures visible at high magnification, may be obscured by texturing at lower magnification - Tergum 3 with apical hair band distinct, hiding surface below, complete to narrowly interrupted (1)
Z - A. placata vs A. simplex - NOTE: these species are extremely similar and hybridize throughout their range - Intermediate specimens may be hybrids
 All the other Andrena species (516)
 A. PLACATA - Facial fovea usually reach level of middle of antennal socket or below - Flagellomere 2 SLIGHTLY shorter than 3 - Propodeal triangle usually finely rugulose in basal half - Tibial scopae usually with dark brown hairs below basitibial plate - Abdominal terga shiny, at least in apical half, with weak tessellation and fine punctures visible at 20x magnification - Terga 5 and 6 hairs usually dark brown - Pygidial plate apex usually narrowly pointed, unless worn (1)
 A. SIMPLEX - Facial fovea usually shorter than level of antennal socket - Flagellomere 2 EQUAL to 3 or VERY minutely longer - Propodeal triangle usually finely tessellate throughout except at extreme base - Tibial scopal hairs pale throughout or only pale brown below basitibial plate - Abdominal terga somewhat dull throughout, with fine but dense tessellation and punctures usually not visible at 20x magnification - Terga 5 and 6 hairs often pale or light brown - Pygidial plate apex usually narrowly truncate, unless worn (1)
Z - A. sigmundi and A. salicifloris vs other Trachandrena and Scrapteropsis
 Not Trachandrena nor Scrapteropsis (475)
 ANOTHER TRACHANDRENA OR SCRAPTEROPSIS - Posterior tibial spur of hind leg straight or uniformly curved throughout its length (43)
 A. SIGMUNDI and A. SALICIFLORIS - Posterior tibial spur of hind leg gently S-SHAPED in outer third (2)
ZZ - Species coded - For internal use only
 zDo not show this character again (520)
 Not yet coded (317)
 Coded (205)
 Coded from junior type (68)
 Coded a little from description and with subgeneric characters (48)
 Coded as far as possible from description and with subgeneric characters (22)
 Coded from primary type (15)
 Needs to be RECODED from specimens (1)
ZZ - Species tested, number of times - for internal use only
 0 (513)
 1 (5)
 2 (1)
ZZ - Type museums - for internal use only
 z Do not show this character again (519)
 US-IL-INHS (136)
 US-DC-USNM (135)
 US-CA-CAS (127)
 US-PA-ANSP (115)
 US-CA-UCR (85)
 US-CA-UCB (64)
 US-KS-SEMC (59)
 US-NY-AMNH (39)
 US-CA-UCD (34)
 CAN-CNC (30)
 US-UT-EMUS (28)
 US-NE-UNSM (26)
 ENG-BMNH (25)
 Z No female types (20)
 US-MI-MSUC (19)
 US-CA-LACM (16)
 US-NC-NCSU (14)
 US-OR-OSAC (14)
 Z Museum unknown (9)
 CAN-PMQ (7)
 US-CO-UCNH (7)
 US-OH-OSUC (6)
 GER-ZMHB (5)
 US-CA-UOP (5)
 GER-SMFD (4)
 US-CA-CPUP (4)
 US-AZ-UAIC (3)
 US-KS-KSUC (3)
 US-NY-CUIC (3)
 US-TX-CTMI (3)
 US-CO-UCMC (2)
 US-FL-FSCA (2)
 US-MA-MCZ (2)
 US-MI-UMMZ (2)
 US-ND-NDSU (2)
 CAN-ULQC (1)
 FRA-MNHN (1)
 GER-DEI (1)
 ITAL-MCSN (1)
 SWED-MZLU (1)
 SWED-NHRS (1)
 SWITZ-MNHN (1)
 SWITZ-NHMB (1)
 US-AZ-NAUF (1)
 US-CA-SJSC (1)
 US-IL-SIUC (1)
 US-MA-BSNH (1)
 US-MN-UMSP (1)
 US-NC-Mitchell (1)
 US-NE-UNSP (1)
 US-PA-CMNH (1)
 US-WA-WSU (1)
 US-WI-MCPM (1)