Somatiosoma messumensis, 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 : 375-377

Somatiosoma messumensis sp. n.

Fig. 27

Etymology: From the type locality, MessumValley in Namibia.

Diagnosis. A completely yellow species that has a small third antennal segment which is a little narrower than height of gena at middle; female has one pair of black spots on tg 7. In some males, distinctive Y-shaped prg visible without dissection.

Description:

Male.

Head: Yellow, oc triangle yellow; fr not visible in profile, at anterior oc 0.4 width of head, narrowed anteriorly, at level of antenae 0.28 width of head; face depressed and with distinct carina in upper half; gena strongly receding, 0.4 height of eye and with several minute pale setulae; ocp in profile broadly visible behind eye margin and almost straight; mouthparts yellow, palp short about half length of proboscis; antenna all yellow except third segment of arista which is brown; third antennal segment round, about equal to height of gena at middle and about 1/3 diameter of eye, second segment with dorsal seta; 3 orb, the anterior inclinate, 1 vt e and 1 vti, oc strongly divergent and long, pvt long and crossed, about 10 minute pale yellow setulae scattered on fr and between orb, postocular setulae in 1 row and postgenal seta long.

Thorax: Entirely pale yellow with most setae pale brown on dorsum and pale yellow on pleura. Chaetotaxy: 1 pprn with 5 setulae around it, 1 strong dc and another about half its length just in front of it, acrs undifferentiated from scutal setulae except short prscut pair, setulae in 8–10 irregular rows at level of transverse scutal suture, prscut pair only a little stronger than other scutal setulae; 1 posthu, 1 short sa and 1 strong pa, scut with 3 pairs of marginals, subapical pair longest, disc of scut with 18 scattered setulae, anepisternum with 1 seta at middle of posterior margin and katepisternum with 1 seta at upper margin, each with several pale setulae in front, more numerous on anepisternum.

Wing: Hyaline with pale yellow veins, costa with minute yellow spine-like setulae from base to R 2+3, distance on costa between R 2+3 and R 4+5 about 0.7 that between R 4+5 and M 1+2, apical section of Cu about 2.5× length of posterior crossvein. Haltere yellow. Legs: All yellow, only fore femur a little dilated, all setae and setulae pale yellow, longest on posterior aspect of fore femur, claws black, short, about 0.5 length of tarsomere 5, apicoventral seta on mid tibia yellow and distinctly shorter than diameter of tibia at apex.

Abdomen: Entirely yellow with a few short and fine pale yellow setulae on each tg, those on tg 5 about 1/4 length of tg.

Postabdomen: All yellow with small hypopygium and distinctive Y-shaped prg.

Female.

As in male, but tending to have brown setae and setulae; also, third antennal segment not so enlarged, but a little less than 1/3 diameter of eye. Postabdomen: st 8 relatively large compared to congeners, thinly sclerotized laterally and with few microtrichia along this margin; hypr entirely membraneous and barely visible, bare and without tubercles; cerc small, oval.

Length: ơ and ^body 1.5 mm, wing 1.7 mm.

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

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: NAMIBIA: 5ơ 19^Karibib District , Tsaobismund 85, 22°22'40''S: 15°44'58''E, 13–15.iv.2001, A.H. Kirk-Spriggs & E. Marais, Malaise traps ( NMNW) ; 1ơ 1^same data ( BMNH) ; 1ơ 1^same data ( NMSA) ; 2ơ 4^same data ( NMWC) ; 1ơ 1^same data ( TAU) ; 3ơ 16^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 ( NMNW) .

Figures

Fig. 27. Somatiosoma messumensis sp. n., (a) ơ hypopygium, lateral, with prg shown also in ventral view, scale bar = 0.15 mm; (b, c) ^postabdomen, lateral (b) and ventral (c), scale bar = 0.2 mm.