Stylogaster spinicercus, Stuke, 2012

Stuke, Jens-Hermann, 2012, A revision of Afrotropical species of Stylogaster Macquart (Diptera: Conopidae), with descriptions of twenty-one new species and an identification key, African Invertebrates 53 (1), pp. 267-267 : 343-347

Stylogaster spinicercus sp. n.

Figs 273–284

Etymology: From Latin spina (thorn), reflecting the thorn­like black spine on the cercus of this species.

Diagnosis: Stylogaster spinicercus sp. n. has the cercus broadened, as does S. amplicercus sp. n., but the two species are easily separable by reference to the black setae on the base of the cercus ( Fig. 281 ) and the unique shape of the surstylus ( Fig. 279 ), having black discal setae.

Description (based on holotype):

Male.

Overall length: ca 6.9 mm.

Head: 1.6 mm high. Eye dark brown, with a few scattered, inconspicuous ommatrichia. Facets on inner side slightly enlarged. Ocelli yellow­brown. Ocellar tubercle blackish brown, with 1 pair of damaged ocellar setae. Ocellar triangle occupies virtually entire frons, reaching as far as antennae ( Fig. 275 ). Ocellar triangle yellow­brown. Frons brown lateral to ocellar triangle, with 1–3 small discernible fronto-orbital setae. Scapus and pedicellus yellow­brown, basal flagellomere brown distally. Arista dark brown with a small yellow-brown area basally, 2 segments evident, situated dorsally on apex of basal flagellomere ( Fig. 276 ). Scapus with a few black setulae dorsally. Pedicellus with black setulae. Shape of antenna as illustrated in Fig. 276 . One distinct black vertical seta. Face pale yellow with silver pruinosity. Occiput black to brown, distinctly silver pruinose; with a row of regularly-arranged small white setulae dorsally, and several longer white setulae ventrally. Some long white setulae on mouth opening. Proboscis pale yellow basally, becoming dark brown distally, except for yellow-brown distal division of labellum. Labrum ca 3.0 mm, labellum approximately same length.

Thorax: Yellow-brown; mesoscutum (with exception of postpronotum), scutellum and mediotergite orange-brown. All undamaged setae on holotype black (supra-alar and dorsocentral setae missing, 1 postalar seta present, all setae on anepimeron missing), with exception of golden seta on propleuron. Two notopleural setae, 1 supra-alar seta, 2 postalar setae, 1 praescutellar dorsocentral seta, 1 apical scutellar seta, 1 seta on anepimeron and 1 seta above fore coxa on propleuron. A few black setulae on anepimeron. Black semi-adpressed setulae on mesoscutum.

Wing: Length 6.1 mm. Generally clothed in microtrichia, but base of bc, base of r 1 and very narrowly basally in r 2+3, base of br, bm, very narrowly at base of dm and cup without microtrichia. Hind margin of wing with black or brown setulae. Venation as in Fig. 278 . Haltere uniformly yellow­brown basally, knob brown, with areas of sensillae at base.

Legs: Fore and mid legs pale yellow. Hind leg darker with brown base and brown dorsal surface of hind femur, and yellow-white subapical area at hind tibia. Legs mainly with black or brown setulae, only fore and mid tibiae and fore femur additionally with pale yellow setulae. Setae on fore and mid coxae whitish yellow, and on hind coxa black. Fore coxa without distinct setae, but with strong white setulae distally. Mid coxa with 1 white seta. Hind coxa without lateral black setulae, but with strong black setulae distally on anterior surface. Hind trochanter without teeth or dense setulae. Mid femur with a row of regularly-arranged black setulae posteriorly on basal half and additionally, a few longer setulae on ventral surface. Mid tibia with short erect black setulae ventrally ( Fig. 277 ). Hind femur with few longer black setulae ventrally. Hind tibia with 2 short black spines on anterior surface. Claws dark brown basally, distally black. Pulvilli pale yellow. Empodia short, brown.

Abdomen: Mainly orange-brown, tergites 2–4 with conspicuous dark brown posterior margin and less distinct brown medial fascia, tergites 5–6 and epandrium slightly darker brown medially ( Fig. 274 ). Tergites with semi­adpressed black setulae. Tergite 1 with long black setulae laterally, tergite 2 on anterior margin with 6 black lateral setae on either side. Terminalia as illustrated in Figs 279–284 . Cercus triangular, conspicuously broadened laterally ( Fig. 281 ). Dorsal margin straight. Cercus with a conspicuous lappet ventrally, clothed in black setae ( Figs 281, 282 ). Surstylus without teeth, but with unique outline, and black setae distally. No setulae on inner surface. Phallus sheath as illustrated in Fig. 283 . Some distinct black setulae distally.

Female. Unknown.

Holotype: ♂ MADAGASCAR:(1) “ Madagascar: Prov. Antananarivo. 46 km NE / of Ankazobe: Anbohitantely 18°11.88'S / 47°16.89'E, 7.­22 xII. 2004, 700m, malaise trap in / sclerophyl forest MG 27­23”; (2) “CASENT 807G539”; (3) “ Holotypus / Stylogaster / spinicercus ♂ / des. Stuke, 2011” ( CAS). Left hind leg and several setae damaged. Abdomen dissected, macerated and deposited in glycerine in a microvial pinned beneath specimen, holotype otherwise in reasonable condition.

Distribution: Endemic to Madagascar.

Bionomics: Sampled in sclerophyl forest at low elevation (700 m).

Figures

Figs 273–278. Stylogaster spinicercus sp. n. (♂ holotype): (273) habitus, lateral view; (274) abdomen, dorsal view; (275) frons; (276) antenna, lateral view; (277) mid leg, anterior view; (278) wing. Not to scale.

Figs 279–284. Terminalia (♂) of Stylogaster spinicercus sp. n. (holotype): (279) surstylus, lateral view; (280) same,dorsal view; (281) cercus, lateral view;(282) same, ventral view; (283) phallus sheath of hypandrium, lateral view; (284) sperm pump and ejaculatory apodeme.Abbreviations:hys – phallus sheath of hypandrium; su – surstylus. Not to scale.