Stylogaster angolensis, 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 : 129-131

Stylogaster angolensis spec. nov.

( Figs 51 –58)

Type material. Holotype ♂: (1) Angola (A30) / 7 mls. W. Gabela / 16–18.iii.1972; (2) Southern / African Exp / B. M. 1972–1; (3) Holotypus / Stylogaster angolensis / spec. nov. / det. Stuke, 2014.

Holotype is deposited in the BMNH. Abdomen dissected, macerated and stored in glycerine in a microvial pinned beneath the specimen. The right hind tarsi and the last segments of the left hind tarsi are missing, but the holotype is otherwise in good condition.

Description of holotype (male). Body length about 4.4 mm. Wing-length 3.9 mm. Head-height 1.0 mm. Head. Eye dark brown, without scattered inconspicuous ommatrichia. Facets on inner side of eye slightly enlarged. Ocelli brown. Ocellar tubercle dark brown, with 1 pair of inconspicuous ocellar setae. Ocellar triangle occupies almost the entire frons and reaches as far as antennae ( Fig. 51 ). Ocellar triangle brown. Frons blackish brown lateral to ocellar triangle, with 2 proclinate fronto-orbital setae. Scape yellowish brown, pedicel and basal flagellomere pale brown to brown. Arista three-segmented, dark brown. Arista situated anterodorsally on basal flagellomere ( Fig. 52 ). Scape without setulae dorsally. Pedicel with black setulae dorsally and anteriorly. Basal flagellomere with a longitudinal fold dorsally. Shape of antenna as illustrated in Fig. 52 . One distinct black vertical seta. Face pale yellow, silver pruinose. Postcranium black dorsally, with only a very small yellow area ventrally, distinctly silver pruinose. Postcranium with line of regularly-arranged small white setulae ventrally. Some long white setulae on mouth opening. Proboscis mainly brown, except for yellowish brown distal division of labellum and yellowish brown base of proboscis. Labrum ca 2.0 mm, labellum approximately the same length. Thorax. Yellowish brown to light brown, with scutum (with exception of postpronotum), scutellum and mediotergite dark brown. All setae black. Two small notopleural setae, 1 strong supra-alar seta, 2 strong postalar setae, 1 prescutellar dorsocentral seta, 1 apical scutellar seta, 1 seta on anepimeron and 1 seta above fore coxa on propleuron. Black semi-adpressed hairs on scutum. Wing generally clothed in microtrichia, but base of bc, base of c, base of br, bm, base of dm and cup all virtually without microtrichia. Hind margin of wing with brown setulae. Venation as in Fig. 53 . Haltere orange-brown, distal part sharply defined dark brown. Legs whitish yellow, with brown hind femur. Legs with black and brown setae, only fore tibia additionally with some white setulae. Fore and middle coxae only with 1 brown seta. Hind trochanter with 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 erect black setulae. All tibiae without conspicuous setulae. Hind tibia with short black spines on anterior surface. Claws only narrowly yellowish brown basally, black distally. Pulvilli yellow or yellowish 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 54–55 . Cercus short, slightly widened laterally, rounded distally. No teeth and only a few inconspicuous bristles at basal junction of cerci. Surstylus small, with a finger-like process anterodorsally, but lacking any black teeth. A small field of erect setulae on inner surface. Two small membranous appendages at the anteroventral corner of surstylus, one additional membranous appendage reaching from the anterior to the ventral margin. Phallus sheath as illustrated in Fig. 55 : Base of phallus sheath protuding and covered with dense black spines.

Female unknown.

Etymology. The species is named after the state of Angola, from which the type material originates. Discussion. Stylogaster angolensis belongs to the Stylogaster nitens group that occurs in central and East Africa (including Madagascar). This species group is defined by the following characters: No outstanding ventral hairs on mid femur; scutum mainly black (exception latifrons); tergites partly brown and tergite 6 almost completely brown; basal flagellum apically rounded, with dorsal arista; shining ocellar triangle occupies almost entire frons and reaches as far as antennae; radial cell R4+5 not deeply curved; phallus sheath of hypandrium with several obvious black bristles on the protuding base (exception kenyensis , rwenzoriensis ); surstylus broad, with a small field of erect setulae on inner surface (exception kenyensis , rwenzoriensis ), a finger-like process may be present anterodorsally and more-or-less distinct black teeth may also occur. The species in the Stylogaster nitens group can be identified with the key given below. Using Stuke (2012) Stylogaster angolensis will key out as Stylogaster nitens .

Distribution. Stylogaster angolensis is only known from Angola to date.

Figures

FIGURES 51 – 53. Stylogaster angolensis spec. nov. (♂ holotype). 51. Dorsal view of frons. 52. Lateral view of antenna. 53. Wing.

FIGURES 54 – 55. Stylogaster angolensis spec. nov. (♂ holotype). 54. Dorsolateral view of cercus. 55. Lateral view of phallus sheath. 56. Dorsal view of cerci. 57. Lateral view of inner surface of surstylus. 58. Lateral view of outer surface of surstylus. mais—membranous appendage on inner surface of surstylus.