Electrapini

Engel, Michael S. & Davis, Steven R., 2021, New genera of melikertine bees with facial modifications in Baltic amber (Hymenoptera: Apidae), Journal of Melittology 2021 (103), pp. 1-52 : 46

Classificatory notes on Eocene bees of the tribe Electrapini (Apidae: Apinae)

The bee tribe Electrapini includes some of the more robust bees found in Eocene deposits, although several exceptions do exist. Species are found as both inclusions in amber as well as in sedimentary deposits and have a generally apine- or bombine-like habitus. Presented here are some notes on the classification of these bees in the hopes of further clarifying their affiliations.

Tribe Electrapini Engel

Key to Genera of Electrapini

1. Metabasitarsus quadrangular, about as long as maximum width ..................... 2

—. Metabasitarsus elongate, 1.5–2× as long as maximum width ................................. ........................................................................................................ Electrapis Cockerell

2(1). Lateral margins of clypeus strongly concave, epistomal sulcus forming an obtuse angle opening toward compound eye; 10 or more distal hamuli; inner metatibial spur minutely ciliate or serrate ......................... Protobombus Cockerell

—. Lateral margins of clypeus nearly linear, epistomal sulcus therefore comparatively straight; 7 distal hamuli; inner metatibial spur densely pectinate, with numerous branches along rachis ...................................... Thaumastobombus Engel