Back to Introduction

Practical key to Family-Group Taxa (Based on Females-From Michener 2000)

1. Scopa, consisting of hairs for carrying pollen, present...2

Scopa absent..11

2. Scopa well developed on metasomal sterna, but absent on hind legs, submarginal cells two, usually about equal in length..Megachilidae

Scopa on hind legs, sometimes also on sterna...3

3. Scopa (sometimes as a tibial corbicula) on hind tibia and usually basitarsus, elsewhere not well developed, tibial scopa thus looking considerably larger than that of femur...4

Scopa on hind femur, where a corbicula is usually evident, scopal hairs usually also present on trochanter, tibia and basitarsus and sometimes on metasomal sterna...6

4. Facial fovea small but well defined; two subantennal sutures well separated on clypeal margin below antenna; apex of marginal cell truncate or sometimes obliquely cut off and thus pointed, but apex well separated from wing margin..Andrenidae (Panurginae)

Facial fovea absent or vaguely defined; one subantennal suture below each antenna, or if two, then the two meeting nearly on clypeal margin...5

5. Long-tongued bees, first two segments of labial palpus elongate, flattened; episternal groove commonly present down to or curving into and joining scrobal groove...Apidae

Short-tongued bees, first two segments of labial palpus similar in form to subsequent segments; episternal groove almost completely absent...Melittidae

6. Facial fovea well developed, covered with short hairs (two subantennal sutures below each antenna, often difficult to see)...Andreninae (Andrenidae)

Facial fovea absent or not well defined, not bearing distinctive short hairs, but if defined, then bare...7

7. Stigma almost always shorter than prestigma, vein r arising almost at apex, margin of stigma in marginal cell concave or straight and not much longer than width of stigma; large robust euceriform hairy bees...Diphaglossinae (Colletidae)

Stigma longer than prestigma, vein r arising near its middle or at least well before apex, margin of stigma in marginal cell straight or convex, much longer than width of stigma; andreniform bees, much more slender than those of above alternative...8

8. Episternal groove extending little below scrobal groove...Nomiinae (Halictidae)

Episternal groove extending far below scrobal groove...9

9. Basal vein only feebly arcuate; glossa bilobed...Colletinae (Colletidae)

Basal vein strongly curved, glossa acutely pointed...Halictinae (Halictidae)

11. Episternal groove extending far below scrobal groove toward ventral surface of thorax (S6 exposed, not bifurcate)...19

Episternal groove absent or curving into scrobal groove...13

12. Glossa pointed; basal vein strongly curved; submarginal cells usually three..Cleptoparasites in Halictinae (Halictidae)

Glossa bilobed or broadly truncate...Hylaeineae (Colletidae)

13. S6 retracted under S5 except for apex; metasomal venter thus appearing to be five-segmented; apex of S6 bilobed, bifurcate, or produced to median spine, frequently bearing rows or clumps of stiff setae...Nomadinae (Apidae)

S6 more fully exposed; the metasomal venter thus recognizably six-segmented; apex of S6 not modifed as above...14

14. Labrum with basolateral angles strongly developed, labrum thus broad at extreme base, where articulated to clypeus; labral shape more or less rectangular and usually longer than broad; forewing with two submarginal cells...Cleptoparasites in Megachilinae (Megachilidae)

Labrum with basolateral angles weakly developed, labrum thus not broadest at extreme base, articulation with clypeus not extending full width of labrum; labral shape often less rectangular, often rounded apically, usually broader than long...Cleptoparasites and social parasites within Apinae (Apidae)