Milichiella quintargentea has been reared from rotten yam tubers. The variety has been collected on cattle dung and in yellow pan, light, and Malaise traps.
Differs from congeners in the slightly brown microtomentose mesonotum and male abdomen with T1-4 brown microtomentose, T5 silvery grey microtomentose except for brown anterior margin.
Male coloration and vestiture: frons subshiny black, ocellar triangle and orbital plates shiny black, lunule brown, basoflagellomere black, face brown microtomentose, palpus black; thorax with mesonotum slightly brown microtomentose, scutellum and pleura brown microtomentose except for big shiny spot on an- and katepisternum, wing hyaline, veins brown, brown spot at tip of vein R1 absent, calypter white, halter black, legs black except for brownish tarsi; abdomen with T1-4 brown microtomentose, T5 silvery grey microtomentose except for brown anterior margin. Female coloration and vestiture: halter yellow, abdomen with T2-4 brown microtomentose, T5 shiny except for microtomentose anterior margin.
Morphology. Head: frons with 2 orbital and 2+0.5 frontal setae, middle frontal seta medioclinate. In males frons 2.0x as wide at posterior margin than at base of antenna, arista about 5.3x as long as basoflagellomere wide, pubescence on arista very short, posterior eye margin with wide notch (6oc, female: 4-5oc) and narrow emargination (1-2oc).
Thorax: 3+1 (var.: 2 dc), 2 prsc, 1+0.7 pprn, 1+0.6+0.6 prs, 2 keps setae, posterior prsc about as long as posterior dc, seta between posterior prsc and posterior dc present. Wing with vein R4+5 and M1 converging (2.5-3.3), and ultimate section of vein M1 1.8-1.9x as long as penultimate section. Fore femur strongly setulose, tibial organ absent.
Male abdomen: posteromedial triangular projection of T1 into T2 present. Tergal chaetotaxy: T2 anterolateral corner with 2-3 lines of setae, T2-5 at least posterior half setulose. S5 1.1x as long as wide, 1.6x as long and 1.9x as wide as S4, heart shaped. Male genitalia with apical seta on cercus longer than epandrial setae; hypandrium long, 1 seta on subepandrial plate, surstylus 0.6x as long as epandrium high, bent posteriorly, dilated apically (1.6x), 2.3x as long as wide, structure of lateral surface smooth, medial surface with 3-5 setulae along anterior margin moving medially basally.
Specimens from India, United Arab Emirates, and Saudi Arabia with 2 dc.
Body length: 2.4 mm; wing length: 2.5 mm.