Usia lata, Loew, 1846, Loew, 1846

Gibbs, David, 2014, A world revision of the bee fly tribe Usiini (Diptera, Bombyliidae) Part 2: Usia sensu stricto, Zootaxa 3799 (1), pp. 1-85 : 21

lata species group

Included species:

U. anatoliensis Gibbs sp. nov.

U. annetteae Gibbs sp. nov.

U. bicolor Macquart, 1855

U. calva Loew, 1869

U. crinipes Becker, 1906

U. greatheadi Gibbs sp. nov.

U. lata Loew, 1846

U. manca Loew, 1846

U. putilla Becker, 1906

U. transcaspica Paramonov, 1950

Diagnosis. This group of 10 species appears to be monophyletic, all having recognisably similar male and, particularly, female genitalia. With strongly pigmented triangular or rectangular vaginal plate, only in U. transcaspica is it less pigmented, brown rather than black, but still conspicuous. Apical sternite (sternite 8) square or wider than long, convex but not strongly so. Apical processes (sternite 9) short, not usually longer than wide, usually a shallow apical emargination between them. Aedeagus apically hooked or at least strongly curved ( U. incognita and U. unicolor similar). Epiphallus membranous, thus variable in shape, never very large or complex. Lateral ejaculatory apodeme very large, protruding beyond epiphallic complex in ventral view ( U. incognita and U. unicolor similar). Basal ejaculatory apodeme longer than aedeagus ( U. incognita and U. unicolor share this character). Gonostylus relatively simple, curved with basal internal blunt process more or less developed.

Discussion. External characters are very diverse, and do not help confirm the monophyly of this group. The occiput can be both densely dusted and entirely shining, some have relatively long vestiture, others are close to being hairless on the mesonotum, most are entirely dark in colour but U. transcaspica is boldly marked with yellow.

The species which show the greatest affinity with the U. lata group are U. incognita Paramonov and U. unicolor Loew , a sibling pair. Both of these have several features of the male genitalia that could place them within the U. lata group. However, the most diagnostic character of the U. lata group, the pigmented vaginal plate, is not present in U. unicolor (female U. incognita not certainly known).