Oroschyromya elgonae, Ebejer, 2009

Ebejer, Martin J., 2009, A revision of Afrotropical Chyromyidae (excluding Gymnochiromyia Hendel) (Diptera: Schizophora), with the recognition of two subfamilies and the description of new genera, African Invertebrates 50 (2), pp. 321-321 : 358-360

Oroschyromya elgonae sp. n.

Fig. 18

Etymology: From the type locality, Mt Elgon in Uganda.

Diagnosis:Yellow species with pair of longitudinal brown stripes on scutum commencing from behind transverse suture and running posteriorly along lateral margin of scut; 1+4 dc setae, but main identification features are in postabdomen.

Description:

Male.

Head: Yellow; fr narrow, at anterior oc only 1.2× width of eye, narrowing only slightly towards antennae where width is 0.8 that at anterior oc; oc triangle brown; ocp yellow, in profile, convex. Eye: elongated oval, 1.7 times as long as high. Gena: slightly recessed and broad, below middle of eye about 1.2× height of eye; pale setulose with 2 long setae on oral margin just below vibrissal angle. ocp, in profile clearly visible behind eye, with short postocular setulae in two irregular rows with additional setulae on disc; isolated lower postgenal seta pale but distinct. Mouthparts small, all pale yellow, palp particularly short oval. Face depressed, barely visible.Antenna with all segments yellow, second with pale long seta dorsally; third segment somewhat elongated ventrally, finely pubescent: pubescence a little shorter than diameter of arista at base; arista black except at extreme base of second segment and whole of first 2 segments where it is yellow. Chaetotaxy: 3 orb, anterior inclinate, middle and posterior orb reclinate, all equidistant from each other; 1 vti and 1 vte a little longer than hindmost orb; pvt crossed, about half length of vt; ocellars a little more than half length of vt; all setae pale; 1 setula in each of the spaces between the orb and about 8 pale setulae scattered on fr.

Thorax: Predominantly yellow; scutum with a small rectangular black patch anteriorly at neck and 2 brown stripes commencing behind transverse suture and extending along lateral margin of scut; remainder of scut and pleura all yellow; mtn brown. Chaetotaxy: 2 pprn, one short, 1 posthu, 2 ntpl, absent pra, 1 sa, 1 pa, 1 short post ia, 1+4 dc, scutal setulae in 4 irregular rows between dc lines; absent longer prescut acrs; scut with usual subapical and basal marginals, but no other setae or setulae; 1 anepisternal at middle of hind margin with a shorter seta above it, 1 katepisternal close to upper hind corner; both sclerites with additional pale setulae in front of setae. All setae on thorax yellow.

Wing: Hyaline with pale yellow tinge over entire membrane; veins pale brown, a little lighter at base; vein closing anal cell convex with a minute stump vein at its middle; distance between R 2+3 and R 4+5 about 0.7 that between R 4+5 and M 1+2; distance between crossveins about twice length of posterior crossvein; length of apical section of vein Cu about 2.8× length of posterior crossvein and about 0.9× distance between crossveins. Haltere pale yellow.

Legs: Yellow, all segments unusually slender for the family and rather long; tarsomere 5 of all legs dark brown in apical third; fine setulae scattered on all pairs of legs, in addition longer setae present on fore femur; mid tibial apicoventral seta absent; claws black except at extreme base and pulvilli normal.

Abdomen: Rather elongate and narrow; dorsally, tg 1 yellow, tg 2 dark brown, tg 3–5 paler brown; only on lateral margins pale; st yellowish white; setulae not numerous, short, about a quarter length of tg, but along hind margin of each tg is a row of uniform brown setae about 2/3 length of tg; tg 6 clearly visible, about half length of tg 5 and 0.8 length of ep; st 5, on each posterolateral corner with a more sclerotized circular part bearing stronger setulae.

Postabdomen: ep yellow, large, higher than long; cerc narrow, elongate and distinctly setose; surs strongly curved, shorter than prg, prg with complex folds at base and 1 long anteroventrally directed seta, long and narrow apically, psg very long and narrow, hyp very broad in profile, ph apd long and narrow, ej apd small, distiph complex with lateral punctate plate towards apex.

Female. Unknown.

Length: ơ body 2.5 mm, wing 2.3 mm.

Holotype: ơ UGANDA: Mt Elgon, Sasa [01°15'N: 34°32'E], montane forest, alt. 3300 m, fogging of Afrocrania volckensi (Cornaceae) , 10–19.ix.1997, T. Wagner (in alcohol, ZSMC).

Figures

Fig. 18. Oroschyromya elgonae sp. n., ơ: (a) hypopygium, lateral; (b) distiph, lateral. Scale bar = 0.2 mm.