Key to Species Groups of Bembecinus

(based on Bohart, 1997, with modifications derived from the manuscript key of F. Gess)

1a. Male flagellomere IX produced into a spine beneath.................... B. tridens group (including discolor, irwini, loriculatus, meridionalis, peregrinus, spinicornis, and tridens subgroups)

1b. Male flagellomere IX simple.................................................. 2

2a. Male flagellum relatively slender; male sterna simple; female foretarsus with apical tarsomere and arolium not unusually large. Afrotropical and Australian Regions....... B. caffer group (including caffer and inermis subgroups)

2b. Male and female flagellum moderately to strongly clavate; male sterna mainly simple, with prong on sternum II in cinguliger (F. Smith), escalerae (Turner), and flavopictus (Arnold); female foretarsus with apical tarsomere and arolium much larger than on other legs. Afrotropical Region................................................................ 3

3a. Flagellum moderately clavate (Fig. 2b); lateral margin of propodeal declivity only slightly compressed, not excised (Fig. 2c); clypeus sub-triangular, only slightly wider than long (Fig. 2a); length of labrum about 0.7–1.0 × its width (Fig. 2a); female forebasitarsus with a sand rake composed of a small number of long spines; male sternum II simple. Nesting in friable (sandy) soil; nest excavation by means of the raking of dry sand; burrow entrance without a turret (F. Gess and S. Gess 1971; F. Gess 1981)....................... B. rhopalocerus group

3b. Flagellum conspicuously clavate; lateral margin of propodeal declivity strongly compressed, widely and deeply excised; clypeus more than twice as wide as long; length of labrum about 0.3–0.4 × its width; female forebasitarsus with dense row of short cilia; male sternum II simple in oxydorcus Handlirsch, with prong in cinguliger (F. Smith), escalerae (R. Turner), and flavopictus (Arnold). Nesting in non-friable (clayey) soil; nest excavation aided by use of water; burrow entrance surmounted by turret (F. Gess and S. Gess, 1975; S. Gess, 1981)............................................... B. oxydorcus group