Oroschyromya peruncinata, 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 : 366-368

Oroschyromya peruncinata sp. n.

Fig. 23

Etymology: From Latin per (a prefix denoting superlative) and uncinata (hooked or spined) referring to the structures of the postabdomen and the spinose cerc.

Diagnosis: Yellow species with very large hypopygium with complex structures easily visible externally; spinose elongate cerc; anterior orb reclinate, posterior 2 orb lateroclinate; 1 strong posterior dc with shorter seta anterior to it.

Description:

Male.

Head:All yellow except for black oc triangle; twice as broad as long; fr strongly narrowed anteriorly: at level of antennae 0.4 width that at level of anterior oc and 0.4 width of one eye viewed from in front. Gena: narrow in front, deeper behind; in profile, below middle of eye, about 0.2 height of eye; yellow and pale haired; ocp in profile barely visible behind eye; short postocular setulae in one irregular row; isolated lower postgenal seta present, but little longer than other setulae. Mouthparts small, all yellow; vibrissal setulae moderately developed. Face poorly sclerotized and depressed.Antenna yellow; second segment pale yellow with distinct short dark seta dorsally; third segment round, finely pubescent: hairs as long as diameter of arista at base; arista black almost throughout and completely bare. Chaetotaxy: 3 strong orb, the anterior slightly reclinate, not at all inclinate, middle and posterior orb reclinate and lateroclinate; pvt distinct and crossed; 1 vti and 1 vte strong; oc short and strongly lateroclinate; about 8 short setulae across middle of fr.

Thorax: Pale yellow and somewhat elongated with dorsal aspect more flattened than is usual in this family. scut with flat dorsal aspect occupying little more than half the area as viewed from above. Chaetotaxy: prpl absent, 0+2 strong dc, scutal setulae in 4–6 irregular rows between dc lines, with one short but distinct prscut pair; 3 or 4 irregular rows of setulae also between dc and sa lines; 1–2 pprn, 1 posthu, 2 ntpl, 1 sa and 1 pa, 1 post ia; 2 pairs of marginal scut setae: one subapical and one basal, no setulae on margin or on disc; anepisternum with 1 strong seta directed backwards at middle of posterior margin, katepisternum with 1 or 2 strong setae at upper posterior corner and a tuft of numerous, fine, long setae at ventral angle. All setae and setulae pale.

Wing: Hyaline with pale yellow veins; discal cell widest at apex; distance between crossveins about equal to apical section of vein Cu; distance between R 2+3 and R 4+5 about 0.5 that between R 4+5 and M 1+2; R 4+5 and M 1+2 parallel towards wing apex. Haltere pale yellow.

Legs: Not modified except for slightly thicker femora; fine setulae scattered on all pairs of legs; in addition longer setae present on fore femur; mid tibial ventral apical seta absent; claws and pulvilli normal; hind trochanter normal.

Abdomen: Entirely yellow and compressed laterally; 5 visible tg, tg 6 very narrow and incorporated as an infolded ridge along anterior margin of ep in its upper half (visible only after dissection). st sclerotized; st 5 with ventrally directed pair of narrow projections and 3 long setae on side of posterior margin. Short setae on disc of tg and some st; marginal setae on tg 3 and tg 4 longer.

Postabdomen: ep well-developed and elongated dorsoventrally with relatively large posteroventrally directed opening; cerc large with 4 strong, but short spines in addition to several fine setulae, hyp distinct with long flange directed towards base of abdomen, ph apd long and free from hyp, ej apd not recognisable (not sclerotised at all), prg in form of large, heavily sclerotized, anterolaterally directed spine and psg modified into a large sclerotized multilobed structure. An elongate sclerite articulating with ventral margins of tg 5 and ep may be a composite of st 5 and prg; distiph very large with sclerotized and membranous components and with some asymmetry at apex.

Female.

Similar to male. Postabdomen: tg 8 consisting of two lateral, discoid-shaped, sclerotized, strongly setose plates as in sibling species affinis sp. n.; margin of tg 5 with complete row of setulae and strong setae.

Length: ơ body 2.3 mm, wing 2.2 mm; ^body 2.1 mm, wing 2.2 mm.

Variation: The male paratype has 1 pprn and a setula adjacent to it; and only one katepisternal. It is a little smaller than the type, but in all other respects identical.

Holotype: ơ TANZANIA: Kimani [08°51'S: 34°10'E], Rt A 104, alt. 1400 m, 29.viii.1996, A. Freidberg ( TAUI).

Paratypes: KENYA: 1^Hunter’s Lodge, nr Kiboko , 02°14'S: 37°43'E, 8–9.viii.2003, A. Freidberg ( TAUI) ; 1^Rt A104, Gilgil , 00°34'S: 36°21'E, 1962 m, 24.viii.2003, A. Freidberg ( TAUI) ; 1^Awasi, Uguedhi , 30 km E of Kisumu, 00°09'S: 35°02'E, 1200 m, 26.viii.2003, A. Freidberg ( TAUI) . UGANDA: 1ơ Kasese, 10 km S, 1500 m, 7.i.1996, I. Yarom & A. Freidberg ( TAUI) .

Figures

Fig. 23. Oroschyromya peruncinata sp. n., ơ: (a, b) head lateral and anterior, scale bar = 0.2 mm; (c) postabdomen, lateral, scale bar = 0.3 mm; (d) postabdomen, posterior, scale bar = 0.25 mm; (e) part of internal hypopygium, lateral, scale bar = 0.05 mm; (f) surs, lateral, scale bar = 0.1 mm.