Milichiella argentea
Differs from congeners in the combination of brown microtomentose mesonotum, 2+1 dc, calypter with brown margin, black legs, and silvery microtomentose male T2-5.
In many collections the name M. argentea has been used for a number of different species with a silvery abdomen. All identifications should therefore be treated with caution.
Male coloration and vestiture: frons subshiny black, ocellar triangle and orbital plates shiny black, lunule black, basoflagellomere black, face brown or greyish microtomentose, palpus black; thorax with mesonotum brown microtomentose but less so than scutellum, scutellum and pleura brown except for shiny spots on an- and katepisternum, wing hyaline, brown spot at tip of vein R1 weak, calypter hyaline with brown margin, halter black, legs black; abdomen with T2-5 silvery microtomentose. Female coloration and vestiture: halter yellow, abdomen with T2-4 brown microtomentose dorsally, 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 2.7x as wide at posterior margin than at base of antenna, arista about 3.7x as long as basoflagellomere wide, pubescence on arista very short, posterior eye margin with wide notch (5-6oc, female: 4-5oc)) and narrow emargination (1-2oc).
Thorax: 2+1 dc, 2 prsc, 1+0.8 pprn, 1+0.7 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 (2.2), and ultimate section of vein M1 2.1x as long as penultimate section. Fore femur slightly stronger setulose, tibial organ ?.
Male abdomen: posteromedial triangular projection of T1 into T2 present. Tergal chaetotaxy: T2 anterolateral corner mostly with 2 lines of setae but triangular extension with more setae, T2-5 with one row of setulae at posterior margin. S5 1.3x as long as wide, 1.9x as long and 2.6x as wide as S4, setulose, posterior margin slightly indented. Male genitalia with 1 seta on subepandrial plate, surstylus 0.8x as long as epandrium high, dilated posteroapically (1.6x), 3.4x as long as wide, structure of lateral surface smooth, medial surface with 3-5 setulae along anterior margin moving medially basally.
Special characters: palpus relatively wide.
Body length: 2.6 mm; wing length: 2.4 mm.
Milichiella argentea belongs to the argentea-group. Species in the argentea-group are characterized by the combination of posterior orbital seta absent (present in M. bimaculata), S5 medium setulose with many setula along posterior margin and some longer setae posterolaterally or with tuft of longer setae posterolaterally, surstylus longer than wide, about as long as epandrium high or longer, usually more than 0.5x as wide, dilated apically, bent posteriorly, usually with 3-5 setulae along anterior margin, line moving medially at base of surstylus.
Milichiella argentea was collected in Malaise traps