Milichiella lacteiventris
Description
Body length: 2 mm; wing length: 2.6 mm.
Male coloration and vestiture: frons subshiny black, ocellar triangle and orbital plates shiny black, lunule brown, basoflagellomere black, face greyish microtomentose, palpus black; thorax with mesonotum slighly brown microtomentose, scutellum and pleura same, except for shiny spots on an- and katepisternum, wing hyaline, veins brown, brown spot at tip of vein R1 very weak, calypter hyaline to yellowish, halter black, legs black except for yellow tarsi; abdomen with T2 brown microtomentose except for silvery posterolateral corner, T3-4 silvery microtomentose except for brown microtomentose posteromedial spot which shimmers silvery depending on light source, T5 silvery microtomentose.
Morphology. Head: frons with 2 orbital and 2 frontal setae, anterior frontal seta medioclinate. In males frons 1.9x as wide at posterior margin than at base of antenna, arista about 3.0x as long as basoflagellomere wide, pubescence on arista very short, posterior eye margin with notch (5oc) and emargination (2oc).
Thorax: 2+1 dc, 2 prsc, 1+0.8 pprn, 1+0.8 prs, 2+0.6 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 (2.7), and ultimate section of vein M1 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 setulose. S5 1.1x as long as wide, 1.8x as long and 1.9x as wide as S4, setulose with longer setae posterolateral. Male genitalia with apical seta on cercus about as long as longest epandrial seta, 1 seta on subepandrial plate, surstylus 0.8x as long as epandrium high, bent posteriorly, dilated apically (1.7x), 1.8x as long as wide, structure of lateral surface smooth, medial surface with 3-5 setulae along anterior margin moving medially basally.
Remarks. Males with completely silvery abdomen could possibly be varieties of M. lacteiventris.
Male coloration and vestiture: frons subshiny black, ocellar triangle and orbital plates shiny black, lunule brown, basoflagellomere black, face greyish microtomentose, palpus black; thorax with mesonotum slighly brown microtomentose, scutellum and pleura same, except for shiny spots on an- and katepisternum, wing hyaline, veins brown, brown spot at tip of vein R1 very weak, calypter hyaline to yellowish, halter black, legs black except for yellow tarsi; abdomen with T2 brown microtomentose except for silvery posterolateral corner, T3-4 silvery microtomentose except for brown microtomentose posteromedial spot which shimmers silvery depending on light source, T5 silvery microtomentose.
Morphology. Head: frons with 2 orbital and 2 frontal setae, anterior frontal seta medioclinate. In males frons 1.9x as wide at posterior margin than at base of antenna, arista about 3.0x as long as basoflagellomere wide, pubescence on arista very short, posterior eye margin with notch (5oc) and emargination (2oc).
Thorax: 2+1 dc, 2 prsc, 1+0.8 pprn, 1+0.8 prs, 2+0.6 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 (2.7), and ultimate section of vein M1 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 setulose. S5 1.1x as long as wide, 1.8x as long and 1.9x as wide as S4, setulose with longer setae posterolateral. Male genitalia with apical seta on cercus about as long as longest epandrial seta, 1 seta on subepandrial plate, surstylus 0.8x as long as epandrium high, bent posteriorly, dilated apically (1.7x), 1.8x as long as wide, structure of lateral surface smooth, medial surface with 3-5 setulae along anterior margin moving medially basally.
Remarks. Males with completely silvery abdomen could possibly be varieties of M. lacteiventris.
Diagnosis
Differs from congeners in the combination of slighly brown microtomentose mesonotum and male abdomen with T2 brown microtomentose except for silvery posterolateral corner, T3-4 silvery microtomentose except for brown microtomentose posteromedial spot which shimmers silvery depending on light source, T5 silvery microtomentose.
Discussion
The HT in AMS has lost it's head, but there are two topotypes in CSIRO, of which one is missing it's abdomen and the other one was dissected.
Distribution
Australasia: Australia (Queensland present); Pacific: Northwestern Pacific (Marianas introduced: presence questionable)
Citation
short diagnosis, abundant light traps, swept from rank vegetation growing in abandoned coconut groves, Guam (Bohart & Gressitt 1951: Filth-inhabiting flies of Guam. – Bull. Bernice P. Bishop Mus. 204: 1-152: 99)
Australasian/Oceanian catalog (Sabrosky 1989: 78. Family: Milichiidae, pp. 555-557. – In: Evenhuis, Catalog Diptera, Australian and Oceanian Regions 86: 557)
type information (Lee, D.J., Crust, M. & Sabrosky 1956: The Australasian Diptera of J. R. Malloch. – Proc. Linn. Soc. N.S.W. 80: 289-?: 322)