Desmometopa m-nigrum
Larvae are coprophagous and necrophagous and adults visit flowers of Apiaceae (Zetterstedt 1848, Carles-Tolrá, 1995), Asteraceae (Lindner 1974), and Grossulariaceae (Britton & Viereck 1905). Females are attracted to honey bees caught by spiders or predaceous insects (Biro 1899, Peyerimhoff 1917, Sabrosky 1983) and Herzig (1938) observed the flies milking aphids.
I. Brake has identified specimens collected on Daucaceae, on Tamarix, and on Ochradenus baccatus.
Differs from congeners in the broad gena, triangular subocular crescent and bilobed polished spot on anepisternum.
Head: 2+1 orbital setae, 2 frontal setae; M-shaped frontal vitta subshining velvet black and especially large and distinct because of narrow gray interfrontal and frontal and orbital plates; ocellar triangle usually ends opposite or slightly in advance of posterior ends of interfrontal plates; interfrontal stripes don't reach anterior margin of frons; basoflagellomere small; palpus gently clavate, not large, yellow, tip and ventral side black; subocular crescent large, triangular, polished; gena height equal to width of basoflagellomere, over 1/4 vertical eye diameter; vibrissal angle 80-90, face gently concave in profile.
Thorax: Mesonotum and scutellum dark gray microtomentose, anepisternum with large bilobed polished black spot posterodorsad to fore coxa, the spot including an adjoining broad anteroventral marginal area of the katepisternum; 2 dc.
Wing hyaline; halter yellow.
Legs black.
2-3 mm