A review of the genus Gibbasilus Londt, 1986 in southern Africa (Diptera, Asilidae)
Author
Londt, Jason G. H.
text
African Invertebrates
2016
57
1
67
81
http://dx.doi.org/10.3897/AfrInvertebr.57.8696
journal article
http://dx.doi.org/10.3897/AfrInvertebr.57.8696
2305-2562-1-67
17A94A5084C2469DAE1DA9E2A78C502B
Taxon
classification Animalia Diptera Asilidae
Gibbasilus arenaceus Londt, 1986
Figs 7, 20A
Gibbasilus
arenaceus
Londt, 1986: 2. figs 1 (habitus), 2 (antenna), 3 (wing), 4-7 (♂ terminalia), 8 (♀ ovipositor), 9-12 (pupa).
Description.
The species was fully described by
Londt (1986)
who provided illustrations of the general habitus, antenna, wing, ♂ terminalia, ♀ ovipositor and pupa as indicated above. The species bears a strong resemblance to the newly described
crinitus
sp. n. (see below). A new illustration of the ♀ ovipositor is here provided for comparative purposes (Fig. 7). The length: depth ratio of the ovipositor = 4.0: 1.
Figures 7-10.
Gibbasilus
species ♀ ovipositors. 7
Gibbasilus arenaceus
Londt, 1986 8
Gibbasilus centrolobus
Londt, 1990 9
Gibbasilus condylus
sp. n. 10
Gibbasilus crinitus
sp. n.
Material examined.
SOUTH AFRICA: 1♀ paratype "South Africa, Cape Prov. / Botterkloof Pass [c.
31°40'S
,
19°16'E
660 m], top of / Sept. 13, 1972, 3119Cd / 2230 ft., ME&BJ Irwin / White sand dune assoc." (NMSA)*; 4♂ 1♀ paratypes "Brandkop [c.
31°42'S
,
19°07'E
875 m] Area / Calvinia District / South-West Cape / 14 October 1964 / B&P Stuckenberg" (NMSA, 1♂ BMNH)*; 6♂ 8♀ "S Africa, Cape #65 / 22 km S Vanrhynsdorp /
31°46'S
,
18°46'E
600 m / Date: 23.xi.1991 / Coll: J.G.H. Londt / Gifberg Edge old land" (NMSA); 1♀ "S Africa, Cape #65 / 24 km S Vanrhynsdorp /
31°48'S
,
18°46'E
600 m / Date: 3.xi.1991 / Coll: J.G.H. Londt / Gifberg. Flat summit" (NMSA); 1♂ holotype "South Africa, Cape Prov / 2.5 mi. S. Elandsbaai [c.
32°19'S
,
18°21'E
10 m], 30 ft / Sept. 16, 1972, 3218Ad / ME&BJ Irwin, / Coastal sand dunes" (NMSA)*; 1♂ 1♀ paratypes "Pakhuis Pass [c.
32°09'S
,
19°02'E
875 m] 950 m / Clanwilliam Dist. / 17-19 Oct 1964 / B+P Stuckenberg" (NMSA)*.
Remarks.
This species bears a strong resemblance to
crinitus
sp. n., described below, but can be separated from that species on features of the male terminalia (inn particular the poorly developed pale setae found along the posterior margin of S8).
Distribution (Fig. 20A), phenology (Table 1) and biology.
Known from six localities approximately centred on the towns of Vanrhynsdorp and Clanwilliam. Collected during the months of September, October and November. Specimens collected by me 22 km south of Vanrhynsdorp, on the road to the Gifberg, were found perching near the tops of the vertical stems of a tall unidentified plant species belonging to the family
Restionaceae
growing on the edge of an old ploughed field (
31°46'16"S
,
18°45'56"E
545 m). Although oviposition was not observed, it is probable that females use their knife-like ovipositors to insert eggs into suitable crevices found on these plants.