Rhabdogaster cornuata, Londt, 2006

Londt, Jason G. H., 2006, A review of the Afrotropical genus Rhabdogaster Loew, 1858 with descriptions of new species (Diptera: Asilidae: Stenopogoninae), African Invertebrates 47, pp. 243-313 : 252-253

Rhabdogaster cornuata sp. n.

Figs 15–17

Etymology: From Latin cornuata (horn). Refers to the horn-like tips of gonocoxal appendages (best viewed laterally).

Description: Based on holotype ơ. The specimen has a cracked head and the left antenna is broken off beyond the pedicel. The head and thorax are slightly greasy making an assessment of pruinescence difficult.

Head: Black, silver pruinose, white setose. Antenna black, setae white. Face entirely pruinose. Mystax entirely white, occupying most of face. Frons and vertex extensively pruinose except for an apruinose stripe between eyes that includes ocellar tubercle. Occiput entirely pruinose. Proboscis and palpi black, setae white.

Thorax: Black, silver pruinose, white setose. Mesonotum with extensive apruinose areas including postpronotal and postalar lobes, a pair of dorsomedial stripes and two large areas anterior and posterior of transverse suture.Pleura extensively pruinose except for apruinose spots on an- and katepisternum. Scutellum pruinose except for hind margin, with approx. 10 sctl s. Postmetacoxal bridge entirely silver pruinose. Legs: cx dark red-brown, silver pruinose, white setose; troc red-brown; fem orange with broad dark red-brown proximal band (more extensive on leg 3); tib orange (leg 3 with dark red-brown distal ends); tar redbrown (leg 3 dark red-brown); mainly white black (a few black setae). Wing 3.9 x 1.4 mm, veins brown-yellow, membrane transparent,unstained, almost devoid of microtrichia (except for some distally). Discal and costal cells entirely without microtrichia.

Abdomen: Black, silver pruinose, white setose.Tergites apruinose middorsally and along hind margins. Sternites entirely pruinose. Terminalia ( Figs 15–17 ): epand in lateral view gradually tapering in slightly undulating fashion to fairly acutely-rounded tips; lobes proximally fairly broadly fused and more strongly sclerotised; hypd in lateral view about as long as external lobe of goncx, fairly straight, with dorsal subapical ridge; broad basally in ventral view, tapering in two stages to narrowly truncate apex. External lobe of goncx shorter than epand lobe and of similar length as hypd, tapering to weakly-sclerotised broadly-rounded apex; well-sclerotised internal lobes welldeveloped, projecting beyond external lobes in a manner reminiscent of bovine horns. Gonostyli in ventral view long (project well beyond horn-like internal lobe of goncx), and straight.

Variation: The female paratypes agree well with the holotype. The face may possess two apruinose spots dorsally.

Holotype: ơ SOUTH AFRICA: Western Cape: ‘ Cape Town [3355S:1825E] / Table Mtn. / 25 Mar. 1979 / J. Londt’.

Paratypes: 2^same data as holotype.

Distribution, phenology and biology (Tables 1, 2): Recorded only from the South African type locality (on Table Mountain in the vicinity of the lower cable-car station). Collected in March.

Similar species: R. poa sp. n., theroni sp. n. and yeti sp. n.

Figures

Figs 6–17. Rhabdogaster species, male terminalia: (6–8) R. atropalpus sp. n., Pakhuis Pass paratype: (6) lateral, (7) dorsal, (8) ventral; (9–11) R. bicolor sp. n., Pietermaritzburg holotype: (9) lateral, (10) dorsal, (11) ventral; (12–14) R. charma sp. n., Uitkyk paratype: (12) lateral, (13) dorsal, (14) ventral; (15–17) R. cornuata sp. n., Table Mt. holotype: (15) lateral, (16) dorsal, (17) ventral. Scale bars = 1 mm.