Hemigymnochaeta trichaeta Kurahashi and Kirk­Spriggs, 2006

Kurahashi, Hiromu & Kirk-Spriggs, Ashley H., 2006, The Calliphoridae of Namibia (Diptera: Oestroidea), Zootaxa 1322 (1), pp. 1-131 : 32-33

Hemigymnochaeta trichaeta Kurahashi and Kirk­Spriggs , sp. nov.

Figs. 21–26 ; 40 .

Description: Length: 5.5–7.3 mm. ♂ Head: holoptic, eyes bare, very closely approximated, almost contiguous; upper facets greatly enlarged, sharply demarcated from smaller ones on lower ½; frons index <0.01 (n =7); frontal vitta yellowish brown anteriorly, reddish brown posteriorly, widened anteriorly and posteriorly, obscured at narrowest point of frons; fronto­orbital plate narrow, yellowish brown, silver­grey dusted, darkened toward vertex, with black setulae anteriorly, with ca. five pairs of ori; parafacial yellowish brown, silver­grey dusted, with black setulae above and below level of joint of pedicel and 1 st flagellomere; face yellowish white, slightly silver dusted, without median carina; facial ridge concolorous with face, slightly silver dusted, flat, broad, setulose on lower ½: mediana narrow, yellowish brown, slightly silver dusted, bare; vibrissarium narrow, yellowish brown, slightly silver dusted, clothed in black hairs; vibrissa well developed; lower facial margin pale brown; genal dilation yellowish brown, slightly silver­grey dusted, entirely clothed in black hairs; postgena concolorous with genal dilation, clothed in black hairs and some yellowish ones posteriorly; occiput concolorous with genal dilation, clothed in yellowish brown hairs, except for some black ones on lower part close to genal dilation; pedicel yellowish brown; 1 st flagellomere yellowish brown, very slightly grey to silver pubescent under certain lights, slightly more than 2 x as long as pedicel; arista brown, darkened on apical ⅔, long plumose for almost entire length. Palpus yellowish, with black setulae.

Thorax: entirely yellowish brown, slightly silver to grey dusted, without distinct stripe; postpronotum, postalar callus and scutellum concolorous with dorsum; prosternum clothed in rather long yellowish hairs; proepisternum bare; katatergite without erect hairs; a few yellowish meral hairs present on upper posterior edge of katepimeron; anepisternum and katepisternum with partly black and yellow hairs; anterior and posterior spiracles pale yellow; postalar wall with tuft of yellow hairs in central circle; tympanic tuft of yellow hairs present; anterior parasquamal tuft absent. Chaetotaxy: ac 3+3; dc 2+3; ia 1+3; pprn 3; ph 3; prs 1; sa 3; pa 2; kepst 1+1; sc 4–6+1, 1–2 basal, 3–4 lateral, 1 discal; n 2; prepst 1–2; prepm 1–2.

Wing: yellowish brown, entirely hyaline; veins brown; tegula yellowish brown; basicosta yellowish brown; subcostal sclerite yellowish brown, pubescent; vein R 1 bare; node of veins R 2+3 and R 4+5 with several black setulae above and below; vein R 4+5 also setulose above and below, setulae extended more than ⅔ way to crossvein r­m above, about ⅔ way to r­m below; vein M 1+2 bent with obtuse angle; section of vein M 1+2 from bend to wing edge slightly inflexed apically; upper and lower calypters brownish, lower calypter tongue­shaped, bare on upper surface. Halter yellowish.

Legs: yellowish brown, mostly with black hairs except for yellowish ones on coxae; fore tibia with 1 p and 3–5 short ad; mid tibia with 1 ad, 2 p and 1 v; hind tibia with row of fine ad including 3 strong but short ones, and 1 short pd, sometimes with 1 short av.

Abdomen: entirely yellowish brown, without pollinosity; tergites virtually without marginal band; tergites 1+2–3 with several lateral marginal bristles; tergites 3–4 with a few lateral discal bristles; 4 th tergite with strong median marginal bristle; 5 th tergite with row of erect marginal and discal bristles; 1 st sternite clothed in yellow hairs; 2 nd sternite clothed in yellow hairs on anterior half, with a few black bristly hairs and bristles on posterior half; hairs on sternites 3–5 black, rather long, some bristly hairs and bristles also present on posterolateral margins.

Postabdomen: normal in size, yellowish brown. ♂ genitalia as illustrated ( Figs 21–26 ).

♀ same as ♂, except in the following respects: Head: dichoptic; eyes virtually bare, separated; frons index at vertex 0.36 (0.35–0.37, n =4); posterior margin of eye straight in lateral view; frons not projecting forward from level of lower facial margin in lateral view; frontal vitta yellowish brown and narrowed anteriorly, 2.5 x width of fronto­orbital plate, just in front of anterior ocellus; fronto­orbital plate yellowish brown anteriorly, slightly darkened towards vertex, brownish grey dusted, with black setulae, provided with ca. 6 pairs of ori; ors 1+1; oc developed; acoc weakly developed; pooc undeveloped; ov and iv well developed; poc parallel; occ 2–3. Thorax: yellowish brown. Wings: lower calypter entirely yellowish brown, without fuscous margin. Legs: entirely pale yellowish brown. Abdomen: similar to that of ♂; abdominal bristles weak.

Differential diagnosis: The new species is very similar to the common species, H. unicolor (Bigot) previously considered conspecific by Zumpt (1956: 139); although he distinguished four forms having intra­specific variability in eye facet size and number of postsutural dc, i.e. macrommatidiata–IV dc, macrommatidiata–III dc, micrommatidiata–IV dc, and micrommatidiata–III dc. The new Namibian species appears to belong to the last form. The size of the upper facets of ♂ eyes is frequently observed to represent intra­specific variation in Calliphoridae . In combination with genitalic evidence, the number of postsutural dc appears to be useful for defining H. unicolor and the new species as two distinct species. Examination of the genitalia of both species indicates that they are similar to one another, but other observations and comparisons indicate that they are species­specific.

Etymology: The specific epithet ‘ trichaeta ’ refers to the presence of three postsutural dc bristles.

Bionomics: Collected in Malaise and hanging fruit traps. The species is probably associated with termites in the larval stage, as are other species of the genus.

Distribution: Namibia.

Type material: Holotype ♂, ‘ Holotype [laser­printed on red card] // Namibia: BWABWATA PARK / Bum Hill campsite (Kwando R.) / 17°46'52''S 23°20'28''E / 10–13.ii.2004 / A.H. Kirk­Spriggs / Malaise trap // Hemigymnochaeta / trichaeta ♂ / Det. H. Kurahashi [laser­printed on white card with red perimeter]’ (NMNW type # T656). Paratypes 5♂, 2♀, same as holotype, except: ‘ Paratype [laser­printed on yellow card] // Hemigymnochaeta / trichaeta ♂ / Det. H. Kurahashi [laser­printed on white card with blue perimeter]’; 1♂, 1♀, same except: ‘A.H. Kirk­Spriggs / F. Suhling / hanging fruit traps’ (holotype and paratypes NMNW type series # T656; 1♂, 1♀, NSMT).

Figures

FIGURES 21–26. Male genitalia of Hemigymnochaeta trichaeta sp. nov. 21. Epandrium, surstylus and cercus, lateral aspect. 22, Cerci and surstyli, caudal aspect. 23. Aedeagus, left lateral aspect. 24. Aedeagus, from behind. 25. Pregonite and postgonite, left lateral aspect. 26. 5th sternite, ventral aspect. Scale bars = 0.2 mm.

FIGURES 39–42. Habitus photographs of Hemigymnochaeta spp. 39. H. maraisi sp. nov. (paratype ♂) (length: 6.5–9.0 mm). 40. H. trichaeta sp. nov. (holotype ♂) (length: 5.5–7.3 mm). 41. H. bequaerti Curran ♂ (length: 7.0–7.7 mm). 42. H. laticeps Zumpt ♂ (length: 8.0–8.2 mm).