Stylogaster schachti, 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 : 334-337

Stylogaster schachti sp. n.

Figs 236–247

Etymology: The species is named in honour of late Wolfgang Schacht (1939–2011), a prominent German dipterist, who spent considerable time building the Diptera collection in Munich and made a major contribution to faunistic research on the Diptera .

Diagnosis: Stylogaster schachti sp. n. belongs to the Stylogaster species-group having long setulae on the mid femur, but without long setulae on the hind femur. It is distinguished from the other species of this group ( S. clementsi sp. n., S. smithi sp. n., S. ranomafanensis sp. n.), by the long basal flagellomere ( Fig. 238 ) and the diagnostic male terminalia ( Figs 242–247 ).

Description (based on holotype):

Male.

Length: ca 5.5 mm.

Head: 1.1 mm high. Eye brown, with a few scattered, inconspicuous ommatrichia. Facets on inner side slightly enlarged. Ocelli pale yellow-brown. Ocellar tubercle brown, with 1 pair of ocellar setae. Ocellar triangle occupies virtually entire frons, reaching as far as antennae ( Fig. 240 ). Ocellar triangle brown. Frons blackish brown lateral to ocellar triangle, with 3 proclinate, fronto-orbital setae. Scapus and pedicellus yellow-brown,

basal flagellomere brown. Arista dark brown, 3 segments evident, situated dorsally on basal flagellomere ( Fig. 238 ). Scapus with few black setulae dorsally. Pedicellus with black setulae. Shape of antenna as illustrated in Fig. 238 . One distinct black vertical seta (1 damaged). Face pale yellow with silver pruinosity. Occiput black, 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 yellow-brown basally, becoming dark brown distally, except for yellow-brown distal division of labellum. Labrum ca 2.2 mm, labellum approximately same length.

Thorax: Yellow-white; mesoscutum (with exception of postpronotum and postalar calli), scutellum and mediotergite blackish brown. All setae damaged with exception of 3 black notopleural setae and 1 white seta on propleuron. Scars of 2 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 4.2 mm. Generally clothed in microtrichia, but base of c, base of br, bm, base of dm, cup and basal half of anal lobe virtually without microtrichia. Hind margin of wing with pale brown setulae. Venation as in Fig. 241 . Haltere uniformly pale yellow, knob brown, with areas of sensillae at base.

Legs: Whitish yellow, hind femur brown dorsally. Legs mainly with black or brown setulae, only fore and mid tibiae with pale yellow setulae. Setae on fore and mid coxae white, setae on hind coxa black. Fore and mid coxae with 1 long yellow seta and additionally with some shorter setulae. Hind coxa with group of black distal setae on inner surface and 1 black seta on outer surface. Hind trochanter without teeth or conspicuous setulae. Mid femur with a row of regularly-arranged black setulae posteriorly on the basal half, and black setulae ventrally, distinctly longer than diameter of mid tibia. Hind tibia with 1–3 short black spines on anterior surface. Claws brown basally, distally black. Pulvilli yellow-white. Empodia short, pale yellow-brown.

Abdomen: Yellow-brown, with tergites 1–2 broadly brown medially, tergites 3–4 with brown posterior margin and small brown median fascia, tergites 5–6 and epandrium mainly dark brown ( Fig. 237 ). Tergites with semi­adpressed black setulae and longer setulae laterally on tergite 5. Tergite 1 with long white setulae laterally, tergite 2 with 4 lateral black setae on anterior margin and 1 or 2 long white setae on either side. Terminalia as illustrated in Figs 242–247 . Cercus rounded distally ( Fig. 242 ). Dorsal margin concave. Cercus with long, strong black spines dorsally ( Fig. 244 ), and small keel ventrally, with 2 black spines. Surstylus with long black setulae mainly at apex ( Fig. 242 ), two black spines distally and few scattered setulae on inner surface. Phallus sheath as illustrated in Fig. 245 . Female. Unknown.

Holotype: ♂ MADAGASCAR: (1) “ Madagascar: Province / Fianarantsoa, Parc National / Ranomafana , radio tower / at forest edge, elev 1130m / 16.­26. November 2003 “; (2) “ 21°15.05'S 47°24.43'E / coll: M. Irwin, R. Harin’Hala / California Acad of Sciences / malaise, mixed tropical / forest MA­02­09B­79”; (3) “ Holotypus / Stylogaster / schachti ♂ / des. Stuke, 2011” ( CAS). Some setae damaged. Left wing damaged and deposited in glycerine.Abdomen dissected, macerated and deposited in glycerine in a microvial pinned beneath specimen, holotype otherwise good condition.

Distribution: Endemic to Madagascar.

Bionomics: Sampled in primary rainforest at moderately high elevation (1130 m).

Figures

Figs 236–241. Stylogaster schachti sp. n. (♂ holotype): (236) habitus, lateral view; (237) abdomen, dorsal view; (238) antenna, lateral view; (239) mid femur, ventral view; (240) frons; (241) wing. Not to scale.

Figs 242–247. Terminalia (♂) of Stylogaster schachti sp. n. (holotype): (242) surstylus and cercus, lateral view; (243) surstylus, ventral view; (244) cerci and surstylus, dorsal view; (245) phallus sheath of hypandrium, lateral view; (246) apex of distiphallus; (247) sperm pump and ejaculatory apodeme. Abbreviations: ce – cercus; su – surstylus. Not to scale.