Stylogaster rwenzoriensis, Stuke, Jens-Hermann, 2015

Stuke, Jens-Hermann, 2015, New Conopid records from the Afrotropical Region (Diptera). Part 1: Paramyopa Kröber, Pseudoconops Camras, Stylogaster Macquart, Thecophora Rondani, and Zodion Latreille, Zootaxa 3963 (2), pp. 101-159 : 150-153

Stylogaster rwenzoriensis spec. nov.

( Figs 114–122 )

Type material. Holotype ♂: (1) Congo Belge: P. N. A. / 12–ii–1953 / P. Vanschuytbroeck & / J. Kekenbosch 2624; (2) Massif Ruwenzori / Kalonge, 2.080 m / gîte Ruwenzori ; (2) Holotypus / Stylogaster rwenzoriensis / spec. nov. / det. Stuke, 2014.

Holotype is deposited in the MRAC. Posterior part of abdomen dissected, macerated and stored in glycerine in a microvial pinned beneath the specimen. The left antenna is missing and sadly the right antenna was lost while photographing the specimen. Several tarsi are missing. The holotype is otherwise in an acceptable condition.

Description of holotype (male). Body length about 6.6 mm. Wing-length 6.0 mm. Head-height 1.6 mm. Head. Eye dark brown, with a few small scattered inconspicuous ommatrichia. Facets on inner side of eye slightly enlarged. Ocelli orange-brown. Ocellar tubercle dark brown, with 1 pair of ocellar setae. Ocellar triangle occupies almost the entire frons and reaches as far as antennae ( Fig. 115 ). Ocellar triangle brown. Frons brown lateral to ocellar triangle, without fronto-orbital setae. Scape and base of pedicel yellowish brown, anterior half of pedicel and basal flagellomere brown. Arista three-segmented, brown, situated anterodorsally on basal flagellomere ( Fig. 116 ). Scape with a few short brown setulae dorsally. Pedicel with black setulae dorsally and anteriorly. Shape of antenna as illustrated in Fig. 116 . One distinct black vertical seta. Face pale yellow, silver pruinose. Postcranium almost completely light yellow, densly silver pruinose. Postcranium with a line of regularly-arranged small white setulae. Some long whitish setulae at mouth opening. Proboscis mainly brown to black, except for yellowish brown distal division of labellum and yellowish brown base of proboscis. Labrum ca 3.5 mm, labellum approximately the same length. Thorax. Yellowish brown to light brown, with scutum only dark brown medially. All setae black. Two long notopleural setae, the slightly longer one situated above the smaller one. 1 strong supra-alar seta, 2 strong postalar setae, 1 prescutellar dorsocentral seta, 1 apical scutellar seta, no seta on anepimeron and 1 seta above fore coxa on propleuron. Short black semi-adpressed hairs on scutum. Wing generally clothed in microtrichia, but bc, base of c, base of br, bm, base of dm, cup, base of r1, and base of r2+3 all virtually without microtrichia. Hind margin of wing with brown setulae. Venation as in Fig. 117 . Haltere orange-brown, distal part sharply defined dark brown. Legs whitish yellow, with hind tibia whitish distally. Legs with black and brown setae. Fore and middle coxae each with 2 black seta. Hind coxa with 1 distinct seta laterally. Hind trochanter without a small triangular tooth. Mid femur posteriorly in distal half with a row of regularly-arranged black setulae curved at their apices. Ventral side of mid femur without black erect setulae. All tibiae without conspicuous setulae. Hind tibia with short black spines on anterior surface. Hind femur with a few longer hairs at base. Claws yellowish brown basally, black distally. Pulvilli yellowish brown to brown. Empodia short, pale brown. Abdomen. Pale brown, with tergite 1 brown, tergites 2–4 with brown posterior margin and broad brown median fascia, tergites 5–6 and epandrium largely dark brown. Tergites with semi-adpressed black setulae, and longer setulae laterally on tergite 5. Tergite 1 with long black setulae laterally, tergite 2 with black setae on either side of anterior margin. Terminalia as illustrated in Figs 118– 122 . Cercus short, not widened laterally, rounded distally. No teeth or obvious bristles at basal junction of cerci. Surstylus broad, with a finger-like process anterodorsally. Distal margin of surstylus lacking any black teeth and with no field of erect setulae on inner surface. Two short membranous appendages on the inner surface of the surstylus. Phallus sheath as illustrated in Fig. 121 : Base of phallus sheath slightly protruding, and without dense black spines.

Female unknown.

Etymology. The species is named after the Rwenzori Mountains, from which the holotype originates. Discussion. Stylogaster rwenzoriensis belongs to the Stylogaster nitens group as defined in the discussion of Stylogaster angolensis and can be identified with the key given above. Using Stuke (2012) the species will key out at couplet 16 but will not fit either of the alternatives. Due to the orange-brown lateral margins of the scutum and the lack of bristles on the phallus sheath of the hypandrium, Stylogaster rwenzorensis is most similiar to Stylogaster kenyensis . Characters to separate these two species are given in the key above.

Distribution. Stylogaster rwenzoriensis is only known from the locus typicus in the Democratic Republic of Congo. The location is situated in the Virunga National Park (National Park Albert, P. N. A.), Democratic Republic of Congo, Orientale Province.

Figures

FIGURES 114 – 117. Stylogaster rwenzoriensis spec. nov. (♂ holotype). 114. Dorsal view of thorax and head. 115. Dorsal view of frons. 116. Lateral view of antenna. 117. Wing.

FIGURES 118 – 122. Stylogaster rwenzoriensis spec. nov. (♂ holotype). 118. Lateral view of outer surface of surstylus. 119. Lateral view of inner surface of surstylus. 120. Dorsolateral view of cercus. 121. Lateral view of phallus sheath. 122. Tip of aedeagus. mais—membranous appendage on inner surface of surstylus.