Isomyia hauwangai Kurahashi and Kirk­Spriggs, 2006

Kurahashi, Hiromu & Kirk-Spriggs, Ashley H., 2006, The Calliphoridae of Namibia (Diptera: Oestroidea), Zootaxa 1322 (1), pp. 1-131 : 36-38

Isomyia hauwangai Kurahashi and Kirk­Spriggs , sp. nov.

Figs. 33–38 ; 43–44 ; 99 .

Description: Length: 9.0–10.0 mm. Slender, metallic fly having hyaline wings and blackish legs. ♂ head: sub­holoptic; eyes glabrous, separated at narrowest point of frons by 1.5 x width of ocellar triangle; frons index 0.15 (0.13–0.16, n =4); frontal vitta blackish brown, narrowed medially, but slightly broader than 1.5 x width of anterior ocellus at narrowest point; fronto­orbital plate densely silver­grey dusted, with rather long fine black setulae anteriorly, provided with ca. eight pairs of ori; parafacial broad, subequal to 3 x width of 1 st flagellomere, densely silver­grey dusted, with brownish setulae on anterior half, with glossy black spot on lower ½; facial plate brown, very slightly grey dusted, median carina short, broad, with median longitudinal incisure; facial ridge concolorous with face, bare except for a few black setulae just above vibrissa; mediana broad, reddish brown, silver­grey dusted, bare; vibrissarium narrow, brown, bare, sub­shining; vibrissa strongly developed; lower facial margin projecting forward more than width of 1 st flagellomere, brown, sub­shining; genal dilation largely blackish, except for upper margin below eye somewhat reddish, grey dusted, clothed in black hairs; postgena concolorous with genal dilation, largely clothed in yellowish white hairs, except a few black ones on anterior lower margin; occiput concolorous with gena, clothed in yellowish white hairs; pedicel brownish orange, sub­shining; 1 st flagellomere brownish orange, pubescent, 3 x as long as pedicel; arista yellowish brown, darkened basally, thickened on basal 1/6, long plumose basal on ¾; palpus long, sub­equal to theca, taeniate, yellowish orange, with black strong setulae.

Thorax: metallic green, with bluish tinge in part, snowy­white dusted anteriorly and medially on scutum, with three undusted sub­shining stripes when viewed from behind; postpronotum, postalar callus and scutellum concolorous with scutum; prosternum with rather long yellowish hairs along lateral margins anteriorly; proepisternum bare; katatergite pubescent; some yellow meral hairs present on upper part of kataepimeron close to row of meral bristles; anepisternum clothed in black hairs; anepimeron clothed in fine long yellow hairs, with a few black bristles; katepisternum clothed in fine long yellow hairs on posterior upper part, with black hairs on anterior ventral parts; anterior spiracle fuscous black; posterior one fuscous black; postalar wall bare; tympanic tuft absent; suprasquamal ridge bare; anterior parasquamal tuft absent. Chaetotaxy: ac 1–2+3; dc 2+4; ia 1+3; pprn 3; ph 4; prs 1; sa 3, 1 fine interstitial between 1 st and 2 nd; pa 2; kepst 1+1; sc 3+2, 1 fine additional basal bristle sometimes present; n 2; prepst 2; prepm 2.

Wings: hyaline, very slightly brownish tinged entirely; veins brown; tegulla black; basicosta black; subcostal sclerite yellowish brown, pubescent; node of veins R 2+3 and R 4+5 with a few black setulae below; vein R 4+5 with ca. 5 black setulae on ½ distance from node to crossvein r­m above; vein M 1+2 bent with obtuse angle, section of vein M 1+2 from bend to wing edge nearly sigmoidal, running toward margin; cell r 4+5 open; calypters whitish; lower one longer than broad, bare on upper surface, with white margin and fringe. Halter yellowish brown.

Legs: black, dull metallic blue tinged on fore and mid coxae, more or less grey dusted, blackish haired; fore tibia with row of 4–5 ad on basal ⅔ and 1 p at apical ½; mid tibia with 1 ad and 1 pd at apical ½, with 3–4 p medially; hind tibia with 2 ad, 2 pd and 2–3 av.

Abdomen: entirely metallic green, brassy tinged, rather densely silver­grey dusted, with trace of median longitudinal stripe on tergites 3–4, black haired; syntergite 1+2 with a few lateral marginal bristles and some bristles on lateral sides; 3 rd tergite with several lateral marginals and 1 lateral discal; tergites 4–5 with row of marginal bristles, tergite 4 with 1 lateral discal, 5 th tergite with row of 3–4 lateral discals; sternites black, black haired; hairs on lateral sides of tergites also black.

Postabdomen: normal in size; 6 th tergite dull metallic blue, with small bristles; epandrium bluish tinged, with small bristles and bristly hairs.

Male genitalia as illustrated in Figs. 33–38 .

♀ Head: dichoptic; eyes glabrous, frons index 0.30 (n =1); frontal vitta broad, parallelsided, slightly narrowed toward base of pedicel, reddish brown, approximately 2 x width of fronto­orbital plate just in front of anterior ocellus; fronto­orbital plate broad anteriorly, narrowed toward vertex, blackish, densely silver­grey pollinose, large glossy black spot present on anterior ½, very sparsely setulose around ors; ors 2+1; oc strong; acoc absent; pooc indistinct; ov and iv well developed; poc parallel; occ absent. Thorax and wing: similar to those of male. Legs: blackish, but reddish brown in part, especially on tibiae; mid tibia with 1 v., otherwise similar to male. Abdomen: with bluish green tinge, more or less reddish on venter, without trace of median longitudinal stripe, marginal and discal bristles weakly developed, often decumbent; 5 th tergite with row of discal bristles. Ovipositor not dissected.

Differential diagnosis: Genitalic evidence and the presence of bright orange antennae indicate that the new species belongs to the distinguenda ­group of species ( sensu Zumpt 1958a: 12 ). This group includes the described species: I. cuprapex ( Villeneuve, 1917) , I. terminata ( Wiedemann, 1830) , I. distinguenda ( Villeneuve, 1917) , I. darwini ( Curran, 1938) , I. cuthbertsoni ( Curran, 1938) and I. faini Zumpt, 1958a . The new species is similar to I. darwini from Rhodesia [= Zimbabwe], but can be easily distinguished from it by the characteristic male genitalia, having the cerci not fused to one another. The male genitalia of the closely­related I. darwini were illustrated by Zumpt (1958a: 57, fig. 16).

Etymology: The species is named in honour of Walter Hauwanga (Technical Assistant, NMNW), who prepared many of the specimens used in this study.

Bionomics: Adults have been collected in Malaise and pitfall traps and by hand. Nothing is currently known of the larval biology.

Distribution: Namibia.

Type material: Holotype ♂, ‘ Holotype [laser­printed on red card] // Namibia: RUNDU DISTRICT / Hamoye Nat. Forest / 18°12''S 19°43''E / 05–08.iii.1999 / E. Marais / Malaise trap // Isomyia / hauwangai ♂ / sp. nov. / Det. H. Kurahashi [laser­printed on white card with red perimeter]’ (NMNW type # T658). Paratypes: 1♂, same data as holotype, except: ‘ Paratype [laser­printed on yellow card]’; 1♂, ‘ Paratype [laser­printed on yellow card] // Namibia: RUNDU DISTRICT / Sovo Area / 18°18'37''S 19°15'36''E / 21–24.IV.2001 / E. Marais, S. Kasch / By hand // Isomyia / hauwangai ♂ / sp. nov. / Det. H. Kurahashi [laserprinted on white card with blue perimeter]’; 1♂, Paratype [laser­printed on yellow card] // BUSHMANLAND / at: 19°22'S 19°36'E / 08.i.–01.ii.1990 / E. Marais / Pres. pitf. traps // Isomyia / hauwangai ♂ / sp. nov. / Det. H. Kurahashi [laser­printed on white card with blue perimeter]’; 1♂, ‘ Paratype [laser­printed on yellow card] // HEREROLAND­WEST at: / 20°31'S 17°29'E / 18.i.–25.ii.1992 / M. Pusch / Pres. pitf. traps // Isomyia / hauwangai ♂ / sp. nov. / Det. H. Kurahashi [laser­printed on white card with blue perimeter]’; 1♀, ‘ Paratype [laser­printed on yellow card] // 3km W Kuru / BUSHMANLAND // 19°56'S 20°38'E / 9–28.I.1991 / E. Marais / Pres. pitf. traps // Isomyia / hauwangai ♀ / sp. nov. / Det. H. Kurahashi [laser­printed on white card with blue perimeter]’ (holotype, 4♂, 1♀, paratypes NMNW type series # T658; 1♂, paratype NSMT).

Figures

FIGURES 33–38. Male genitalia of Isomyia hauwangai sp. nov. 33. Epandrium, surstylus and cercus, left lateral aspect. 34. Cerci and surstyli, caudal aspect. 35. Aedeagus, left lateral aspect. 36. Aedeagus, from behind. 37. Pregonite and postgonite, left lateral aspect. 38. 5th sternite, ventral aspect. Scale bars = 0.2 mm.

FIGURES 43–44. Habitus photographs of Isomyia hauwangai sp. nov. (holotype ♂) (length: 9.0–10.0 mm). 43. Dorsal aspect. 44. Lateral aspect.

FIGURES 99–104. Distributions of Namibian Calliphoridae species. 99. Isomyia hauwangai sp. nov. 100. I. natalensis (Villeneuve). 101. I. tristis (Bigot). 102. Zumba antennalis (Villeneuve). 103. Perisiella anchora (Wiedemann). 104. Pseudorhyncomyia braunsi (Villeneuve).