Sisyrnodytes ausensis, Londt, 2009

Londt, Jason G. H., 2009, A review of Afrotropical Sisyrnodytes Loew, 1856 (Diptera: Asilidae: Stenopogoninae), African Invertebrates 50 (1), pp. 137-137 : 146-147

Sisyrnodytes ausensis sp. n.

Figs 13, 14 , 41

Sisyrnodytes brevis (misidentification of material from Aus): Oldroyd 1957: 84; 1974: 73.

Etymology: The name is derived from the type locality of Aus.

Description:

Male (based on holotype in good condition).

Head: Dark red-brown to black, white setose. Antennae: Dark red brown except for distal half of postpedicel and tip of style which are pale brownish. Scape and pedicel white setose. Major ventral setae of pedicel do not project beyond level achieved by postpedicel (are broken). Basal element of style short (slightly longer than broad). Eye to face width ratio 1.7:1. Mystax longish, white. Frons and vertex white setose. Laterally situated frontal setae extending below antennal sockets. Occipital and postocular setae white. Palps and proboscis dark red-brown, palpi dark red-brown setose, proboscis white setose.

Thorax: Dark red-brown to black. Pronotum white setose. Mesonotum entirely setose except for narrow paramedial strips, sutural and postsutural spots. Lateral macrosetae white (npl) and yellow (spal & pal); other setae white (anteriorly) and glistening yellowish (posteriorly). Scutellum apruinose with poorly defined transverse groove (has a crinkled appearance); disc asetose, c. 20 yellow apical setae. Pleural setae white and yellowish.Anepisternum white setose, katepimeron asetose, katatergals pale yellow, long, shafts more or less smooth. Legs: Dark red-brown, mainly white setose (there are some black setae at distal tips of tibiae and ventrally on tarsi). Claws longish, dark red-brown; empodia short yellowish; pulvilli minute to absent. Wings 4.4× 3.1 mm; C yellow setose basally; membrane transparent but brownish stained proximally (staining extends to end of costal cell and is weaker posteriorly). Haltere yellow with pale brown stalk. Abdomen: Dark red-brown, terga with tiny setae medially (appearing asetose), and moderately long white setose laterally, Sterna long wavy yellowish setose.

Genitalia ( Figs 13, 14 ): Epandrium reduced and simple in structure, proctiger extending well beyond it. Gonocoxite with external lobe tapering to narrowly-rounded tip, internal lobe longish, with slightly bilobed distal end. Gonostylus slightly longer than internal lobe of gonocoxite and simple in structure. Hypandrium flattish, sub triangular in ventral view, narrowing a little before midlength, medial lobe with almost parallel sides extending well beyond outer lobe of gonocoxite, but falling short of the distance attained by internal lobe. Aedeagus fairly slender with small, blunt tip. (Note: The genitalia were attached to a card pinned under the specimen and appeared to have been cleared (probably by Oldroyd). This card was removed, placed in warm KOH (which caused the genitalia to become detached from the card) and stored in a vial containing an alcohol/glycerine mixture after being illustrated.)

Female: Similar to male but slightly larger and have far more yellow to pale orange setae. One female has the head entirely yellowish setose except for some ventral occipitals; pronotum yellow-white setose; mesonotum entirely yellow setose; legs yellow setose except for the dark red-brown setae as in male; abdomen with yellow setae laterally (some extending along posterior margins of terga). The other female is almost entirely pale orange setose.

Variation: Wing length ơ c. 4.4–4.7 mm, ^c. 5.3 mm. (Three specimens have the tips of their wings damaged making measurements approximate, while one female has badly damaged wings that were not measured.)

Holotype: ơ NAMIBIA: ‘Aus. [26°40'S: 16°16'E] / Dec. 1929 ’, ‘ S.W. Africa. / R.E. Turner. / Brit. Mus. / 1930-113’ ( BMNH). The specimen is pinned laterally, double mounted on a strip of cellulose and had a little green verdigris (cleaned) above and below.

Paratypes: 3 ơ 3^same data as holotype ( BMNH) .

Distribution, phenology and biology: Known only from the type locality ( Fig. 41 ) and collected in December (Table 1).

Similar species: This species is similar to brevis and oligotrichus .

Figures

Figs 13–18. Sisyrnodytes species, ơ terminalia: (13, 14) S. ausensis sp. n., holotype, lateral (position of aedeagal base faintly indicated) and ventral; (15, 16) S. brevis (Macquart, 1838), Worcester, lateral and ventral; (17, 18) S. curtus (Wiedemann, 1819), 7 mi. N. Vanrhynsdorp, lateral and ventral. Scale lines = 1 mm.

Fig. 41. Distribution of Sisyrnodytes ausensis sp. n. (•), brevis (Macquart, 1838) (·) and niveipilosus Ricardo, 1925 (9).