Abdomen, Tergum 2, Pale apical hair bands | Abdomen, Tergum 2, Surface texture in middle of tergum | Abdomen, Tergum 2, pitting spacing on longitudinal center of segment - - Note, ignore pitting patterns along the rim and the very base of the segment | Body length, in mm | Flight Season - Month | Head, clypeus, surface texture between pits | Head, facial fovea, length | Head, labral process, margin - - Note, often you will want to choose more than one category | Head, vertex height, distance from lateral ocelli to rear margin of head | Legs, rear legs, tibial scopal hair formation | Locality where specimen was collected in Canada | Locality where specimen was collected in USA | Region where specimen was collected | Subgenus, Classic LaBerge Version, note that the subgenera are being actively revised and this is the traditional classification - primarily useful for Andrena experts | The Andrena female key is partially based on species revisions and diagnoses by Wallace LaBerge, Theodore Mitchell, and others, but primarily on direct scoring of specimens located in the Logan Bee Laboratory by a group of bee biologists. As of 2024, we are actively revising this guide’s text and images. We are always looking for collaborators to work on western species. | The opening page offers a limited set of characters from which to choose. Click on any trait states that you can confidently assess, and then use the SEARCH button to activate your choices. This will return a set of species matches on the left . Next, select SIMPLIFY and the screen will present a new set of characters. | This guide is complete for Andrena found East of the Mississippi, but incomplete for western bees, and some western species will not completely resolve. It is very important to note that species to the East of the Mississippi have extra questions that differentiate tricky groups of similar specimens, but western species do not. | Thorax, Pronotum, Humeral Angle - Note, very difficult to determine unless you have had practice, so you may want to skip | Thorax, propodeal triangle, percentage of LENGTH coarsely sculptured | Wings, forewing, number of submarginal cells

Check boxes for all that apply. If uncertain, skip character or select several states. Then click on any search button.
Navigate with above index or scroll bar.

Number scored for a state is in green.

1. The opening page offers a limited set of characters from which to choose. Click on any trait states that you can confidently assess, and then use the SEARCH button to activate your choices. This will return a set of species matches on the left . Next, select SIMPLIFY and the screen will present a new set of characters.    [Explain]

1DO NOT CLICK THIS BUTTON -- Please click on the EXPLAIN button for a link to a guide to using Discover Life. A link to a Google Drive folder with additional keys and other identification resources is also provided.   


2. The Andrena female key is partially based on species revisions and diagnoses by Wallace LaBerge, Theodore Mitchell, and others, but primarily on direct scoring of specimens located in the Logan Bee Laboratory by a group of bee biologists. As of 2024, we are actively revising this guide’s text and images. We are always looking for collaborators to work on western species.    [Explain]

1DO NOT CLICK THIS BUTTON -- David Cappaert has created a guide to the Andrena characters listed in the Discover Life Andrena key. Please click on the EXPLAIN button for a link to the website.   

3. This guide is complete for Andrena found East of the Mississippi, but incomplete for western bees, and some western species will not completely resolve. It is very important to note that species to the East of the Mississippi have extra questions that differentiate tricky groups of similar specimens, but western species do not.

1261. Click here to key bees from east of the Mississippi - excludes western species and those rare and potentially invalid species we have not seen    1312. Click here to include all eastern species and exclude all western species    4503. 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    5204. 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   

4. Region where specimen was collected

4791. United States    1672. Canada    2183. Mexico    74. South of Mexico    519Zz Do not show this character again   

5. Locality where specimen was collected in USA    [Explain]

18AK    57AL    64AR    149AZ    262CA    155CO    92CT    102DC    103DE    27FL    91GA    91IA    129ID    108IL    105IN    93KS    99KY    38LA    92MA    103MD    76ME    100MI    96MN    102MO    48MS    116MT    99NC    76ND    120NE    79NH    111NJ    147NM    167NV    103NY    104OH    74OK    140OR    111PA    92RI    91SC    105SD    98TN    118TX    142UT    101VA    79VT    124WA    93WI    104WV    148WY    519Zz Do not show this character again   

6. Locality where specimen was collected in Canada

73Alberta    106British Columbia    54Manitoba    50New Brunswick, Nova Scotia or Prince Edward Island    10Newfoundland or Labrador    16Northwest Territories or Nunavut    91Ontario    76Quebec    57Saskatchewan    14Yukon    519Zz Do not show this character again   

7. Flight Season - Month

501. January    1762. February    3073. March    3564. April    3745. May    3276. June    3017. July    2288. August    1539. September    10010. October    5511. November    1812. December   

8. Body length, in mm    [Explain]

94    305    826    1967    3068    3769    39810    37311    30412    20213    12514    7115    3216    917    318    521Zz Do not show this character again   

9. Head, vertex height, distance from lateral ocelli to rear margin of head    [Explain]

2511. Less than 1 ocellar diameter    2792. About 1 ocellar diameter    2303. More than 1 to 1.5 ocellar diameters    674. More than 1.5 to 2 ocellar diameters    385. Two or more ocellar diameters   






10. Head, facial fovea, length

124Extremely long, reaching to below level of top margin of clypeus    305Long, reaching to below level of lower margin of antennal socket, sometimes to level of top margin of clypeus    167Moderate, reaching level of lower margin of antennal socket    119Moderate, reaching level of middle of antennal socket    51Short, reaching level of upper margin of antennal socket    21Very short, not reaching level of upper margin of antennal socket   







11. Head, clypeus, surface texture between pits    [Explain]

228DULLED throughout    345SHINY in center or apically and DULLED at least along dorsal and lateral margins    116SHINY throughout   




12. Head, labral process, margin - - Note, often you will want to choose more than one category

2511. Entire - Apical margin concave or straight across, aka continous, without any concave section in the middle    2482. Weakly emarginate - Meaning that in the middle of the apical edge, the margin is subtly concave, if you look closely    1293. Emarginate, but not bidentate - Meaning that the central portion of the margin is clearly concave but does not go quite to the level of being tooth like at the edges - - see bidentate state    1104. Bidentate - IMPORTANT NOTE...Be aware that in many bidentate species you have to turn the specimen almost upside down to view the bidentate feature of the labral process, which is, at times, not visible from the top surface of the process but hidden under a minute lip that projects from the tip of the top surface, usually this feature presents as a very deeeeeply indented rounded notch in the center of the apical margin and to either side are somewhat toothlike lobes    265. Pointed - same as bidentate character but the teeth are pointed like little vampire teeth and not blunt - - UNCOMMON    16. UNCOMMON - With a median projection   







13. Thorax, Pronotum, Humeral Angle - Note, very difficult to determine unless you have had practice, so you may want to skip

236ABSENT, rear margin of pronotum smoothly rounded    289Present, but WEAK, with slight angle but not with distinct corners    115Present, distinctly squared off forming CORNERS   




14. Thorax, propodeal triangle, percentage of LENGTH coarsely sculptured    [Explain]

3450 percent - surface uniformly smooth    2985 - 50 percent    16150 - 80 percent    102100 percent - triangle completely filled   





15. Legs, rear legs, tibial scopal hair formation

3331. Hairs simple and unbranched IN CENTER of outside face of tibia, but hairs along outer edges of tibia can be branched or unbranched    572. Weakly branched throughout, only 1-3 branches per hair and/or branches very weak    953. Plumose, with many branches per hair    1As in stipator   





16. Wings, forewing, number of submarginal cells

842    4743   



17. Abdomen, Tergum 2, Pale apical hair bands

1511. Complete, not interrupted medially    2672. Narrowly interrupted medially, no more than half of apical margin bare    2223. Broadly interrupted, more than half of apical margin bare    2134. Absent, hair on apical margin not denser than elsewhere   

18. Abdomen, Tergum 2, pitting spacing on longitudinal center of segment - - Note, ignore pitting patterns along the rim and the very base of the segment

209Absent or indistinct and difficult to see even at high magnification    112Dense, separated by 1 pit width or less    193Separated by 1-3 pit widths    75Separated by 3-6 pit widths   





19. Abdomen, Tergum 2, Surface texture in middle of tergum

315GRANULAR or with fine lines, usually dull but may still be somewhat shiny    154SMOOTH and SHINY   



20. Subgenus, Classic LaBerge Version, note that the subgenera are being actively revised and this is the traditional classification - primarily useful for Andrena experts    [Explain]

2Anchandrena    45Andrena s.str.    2Aporandrena    3Archiandrena    3Augandrena    6Belandrena    91Callandrena    1Celetandrena    1Charitandrena    1Chaulandrena    29Cnemidandrena    2Conandrena    1Cremnandrena    4Dactylandrena    3Dasyandrena    9Derandrena    25Diandrena    1Erandrena    25Euandrena    1Geissandrena    2Genyandrena    7Gonandrena    9Hesperandrena    7Holandrena    1Iomelissa    1Larandrena    13Leucandrena    30Melandrena    22Micrandrena    3Nemandrena    2Notandrena    3Oligandrena    22Onagrandrena    1Opandrena    1Oxyandrena    10Parandrena    1Pelicandrena    7Plastandrena    2Psammandrena    3Ptilandrena    4Rhacandrena    2Rhaphandrena    24Scaphandrena    2Scoliandrena    19Scrapteropsis    11Simandrena    1Taeniandrena    18Thysandrena    25Trachandrena    15Tylandrena    1Unassigned    1Xiphandrena    32ZUnassigned    518Zz Do not show this character again