Gibbasilus crinitus, Londt, Jason G. H., 2016

Londt, Jason G. H., 2016, A review of the genus Gibbasilus Londt, 1986 in southern Africa (Diptera, Asilidae), African Invertebrates 57 (1), pp. 67-81 : 77-79

Taxon classification Animalia Diptera Asilidae

Gibbasilus crinitus sp. n. Figs 1, 10, 15, 16-19, 20A

Etymology.

L. m. crinitus - hairy; refers to the mediodistal cluster of black setae found on S8.

Description.

Based on type series consisting of 5♂ 3♀.

Head: Black, fine silver pruinose, black and white setose. Antenna: Black, fine silver pruinose, scape and pedicel black setose. Segmental ratios (scape as 1) = 1: 0.6: 1.5: 0.7 (elements of style = 0.2, 0.4, 0.1). Style composed of three elements (small basal segment-like element, long middle rod-like element, terminal seta-like sensory element). Face black, silver pruinose, profile plane. Mystax long, well-developed, extending from epistomal margin to antennal sockets, macrosetae black (laterally) and white (centrally) down entire depth of face. Frons and vertex black, weakly silver pruinose, fine, long, black setose. Ocellar tubercle with long, fine, black setae. Postocular (occipital) region black, silver pruinose, mostly black setose dorsally, white laterally and ventrally. Palpi 2-segmented, segment 1 white setose, 2 black setose. Proboscis shiny black, fine white setose.

Thorax: Dark red-brown to black, silver pruinose, black, pale yellow and white setose. Pronotum dark red-brown to black, white setose. Mesonotum black, entirely fine silver pruinose. Acrostichals numerous, mane-like, predominantly black except for a few white setae anteriorly and a cluster of fine white setae posteriorly. Dorsocentrals well-developed, black, extending both anterior and posterior of transverse suture. Mesonotal macrosetae: Strong, pale yellow, 2 npl, 2 spal, 1 pal. Scutellum black, entirely dull silver pruinose; disc fine white setose, 2 long, pale yellow apical macrosetae. Pleura: Dark red-brown to black, entirely dull silver pruinose, white setose. Katatergal setae weak, white. Anatergites uniformly dull silver pruinose, asetose. Mediotergite fine white setose medially. Legs: Coxae Dark red-brown to black, fine, dull silver pruinose, fine white setose. Trochanters shiny black, apruinose, fine white setose. Femora slightly inflated, entirely dark red-brown to black, macrosetae mostly black (except for a few pale orange anterodorsally on mes- and metathoracic femora). Tibiae orange except for dark red-brown to black distal quarter, macrosetae mostly black (a few orange). Tarsi dark red-brown with black macrosetae (except for a few yellow on Tar 1). Claws dark red-brown to black, pulvilli and empodia well developed, brown. Wings: ♂ 7.2 (6.3-7.7) × 2.4 (2.1-2.6) mm, ♀ 6.6 (6.2-7.3) × 2.1 (2.1-2.2) mm. Veins dark red-brown to black, cells r1, m3, and cua closed and stalked, membrane unstained, entirely transparent except for slight opaqueness resulting from presence of microtrichia primarily distally and broadly along hind margins. Halter pale yellow to orange.

Abdomen: Entirely dark red-brown to black, extensively dull silver pruinose, weakly along lateral margins of T2-4 and S2-4 which are shiny apruinose. Terga fine short white setose except for narrow mid-dorsal strip of tiny black setae, T1-5 with 2-3 laterally situated pale yellow, weak macrosetae (progressively diminishing in size towards terminalia). Sterna fine, longish setose.

Abdomen: Entirely dark red-brown to black, extensively dull silver pruinose, except lateral margins of T2-3 which are shiny apruinose. Terga fine short white setose, T1-4 with 1-2 laterally situated pale yellow macrosetae (progressively diminishing in size towards terminalia). Sterna fine, longish setose. ♂ genitalia (Figs 16-19): Epandrium three times longer than deep in lateral view, with widest part at approximately mid-length; fairly broadly rounded distally; converging slightly subapically in dorsal view. Gonocoxite one-third as long as epandrium, smoothly rounded distally. Gonostylus elongate almost half the length of epandrium, broad basally in ventral view, tapering distally to an upwardly directed process seen in lateral view. Hypandrium short, about half as long as gonocoxite in lateral view, posterior margin slightly indented medially. Aedeagus long and thin, S-shaped distally, terminating in a 3-pronged tip. Posterior margin of S8 with a medial, rounded swelling bearing a row of fairly long black setae. ♀ ovipositor (Fig. 10): Elongate, laterally compressed and knife-like. Length: depth ratio = 4.7: 1.

Holotype.

SOUTH AFRICA: 1♂ "South Africa W Cape / Kagga Kamma Nat. Res. / 32°45'12"S, 019°34'23"E / J&A Londt 12.xi.2015 / 1080 m Sandy vynbos" (NMSA).

Paratypes.

SOUTH AFRICA: 2♂ 1♀ "South Africa, C.P. / Clanwilliam, 32°10'S, 18°53'E. 30.ix.1986 / M.W. Mansell & J.H. / Hoffmann", "Collected / at light" (NMSA);# 1♂ 1♀ with identical label data as holotype (NMSA); 1♂ 1♀ "South Africa W Cape / 13 km S Kagga Kamma / 32°49'42"S, 019°37'32"E / J&A Londt 8.xi.2015 / 1270 m Rocky, restios" (NMSA).

Remarks.

This species bears a strong resemblance to arenaceus , but can be separated from that species on features of the male terminalia (mainly on the well-developed black setae found along the posterior margin of S8). While crinitus sp. n. may eventually prove to be a variant of arenaceus there is presently insufficient material to verify that possibility. It should be noted that the material collected at Clanwilliam was recorded previously by Londt (1990) under the name arenaceus .

Distribution (Fig. 20A), phenology (Table 1) and biology.

Known only from three localities. Collected in September and November. Specimens collected by me were taken resting on the stems of an unidentified species of Restionaceae or sunning themselves on rocks. The species being found sympatrically with condylus , the general habitat being illustrated in Fig. 15.