Somatiosoma grandicornis, 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 : 373-375

Somatiosoma grandicornis sp. n.

Fig. 26

Etymology: From Latin grandis (large) and cornu (horn), and refers to the large third antennal segment.

Diagnosis. Uniformly yellow species that has no crossed apical setulae on scut and no spots on apical tg of female abdomen; third antennal segment distinctly enlarged; in male, viewed in profile, about half diameter of eye, in female, just a little less. Male postabdomen: prg greatly elongated, external to lower margin of ep and ending in two broad setae.

Description:

Male.

Head: Yellow, oc triangle black; fr not visible in profile, at anterior oc 0.4 width of head, narrowed anteriorly; face depressed and with distinct carina in upper half; gena strongly receding, 0.3 height of eye and with several minute pale setulae; ocp in profile broadly visible behind eye margin and convex; mouthparts yellow; antenna all yellow except third segment of arista which is black; third antennal segment large and round, reaching almost half diameter of eye, second segment with dorsal seta; 3 orb, the anterior inclinate, 1 vte and 1 vti, oc divergent and long, pvt short but distinct and crossed, about 30 minute pale brown setulae scattered on fr and between orb, postgenal seta long.

Thorax: Entirely pale yellow with most setae pale brown on dorsum and pale yellow on pleura. Chaetotaxy: 1 pprn with 4 setulae around it, 1 strong dc and another about 1/3 its length just in front of it, acrs undifferentiated from scutal setulae except short prscut pair, setulae in 10 irregular rows at level of transverse scutal suture between dc lines, 1 posthu, 1 short sa and 1 strong pa, scut with 3 pairs of marginals, subapical pair longest and basal pair short, about 1/4 length of subapicals, lateral pair intermediate in size, disc of scut with 6–17 scattered setulae, anepisternum with 1 seta at middle of posterior margin and katepisternum with 1 seta at upper posterior corner, each with several pale setulae in front, more numerous on anepisternum.

Wing: Hyaline with pale yellow veins, costa with minute black spine-like setulae from base to R 2+3. Haltere yellow.

Legs: All yellow, only fore femur a little dilated, all setae and setulae pale brown, longest on posterior aspect of fore femur, claws black, apicoventral seta on mid tibia distinctly shorter than diameter of tibia at apex.

Abdomen: Entirely yellow with a few short and fine brown setulae on each tg.

Postabdomen: All yellow with small hypopygium and distinctive elongated prg ending in 2 stout setae.

Female.

As male, but tending to have darker brown setae and setulae; also, third antennal segment not so obviously enlarged, but about 1/3 or slightly more than diameter of eye. Postabdomen: st 8 not as clearly oval as in eremicolum , setulose along lateral margin, and along midline of long axis distinctly more sclerotized; hypr bare but with minute tubercles; spermatheca small and dark and duct not sclerotized.

Length: ơ body 2.0 mm, wing 1.8 mm; ^body 2.1 mm, wing 1.9 mm.

Variation: Very little variation noted other than the number of setulae on the dorsum of the scut.

Holotype: ơ NAMIBIA: Brandberg , Mason Shelter, 21°04'42"S: 14°35'33"E, 5–14.iii.2002, alt. 1750 m, light trap, A.H. Kirk-Spriggs ( NMNW).

Paratypes: 2ơ 10^same data ( NMNW) ; 1ơ 2^same data ( NMSA) ; 1^Brandberg, Hungarob R., 1200 m, 21°13'05"S: 14° 31'01"E, light trap, 9.xi.1998, A.H. Kirk-Spriggs ; 1ơ 1^Brandberg, Messum Valley, 700 m, 21°13'29"S:14°30'98"E, Malaise trap, bushy Karoo-Namib shrubland, 5–17.iv.1999, S. Van Noort & S.G. Compton (in alcohol, NMNW) ; 4^Karibib District, Tsaobismund 85 at 22°22'40''S: 15°44'58''E, 13– 15.iv.2001, A.H. Kirk-Spriggs & E. Marais, Malaise traps ( NMNW) . MADAGASCAR: 1ơ 3^coastal dry scrub north of Toliara, 15.ii.1984, M.von Tschirnhaus (in alcohol, ZSMC) ; 1ơ between Ambrorompotsy (west) and Tranoroa (east), 23 km E Ampanihy, 24°41'S: 44°55'E, 22.ii.1984, M. von Tschirnhaus (in alcohol, FBUB) . YEMEN: 2ơ 2^Ta’izz, 5.i–2.ii.1998, light trap, A.van Harten & M. Mahyoub ( NMWC) .

Figures

Fig. 26. Somatiosoma grandicornis sp. n.: (a) ơ head, lateral; (b) ơ hypopygium, lateral, with prg shown also in ventral view; (c, d) ^postabdomen, ventral (c) and lateral (d). Scale bar = 0.35 mm in Fig. 26a and 0.2 mm in Figs 26b–d.