Sisyrnodytes subater Oldroyd, 1957

Londt, Jason G. H., 2009, A review of Afrotropical Sisyrnodytes Loew, 1856 (Diptera: Asilidae: Stenopogoninae), African Invertebrates 50 (1), pp. 137-137 : 166-168

Sisyrnodytes subater Oldroyd, 1957

Figs 33, 34 , 42

Sisyrnodytes subater: Oldroyd 1957: 87–88 ; 1974: 74; 1980: 368 (catalogue).

Redescription:

Male (based on holotype in good condition; right metathoracic leg broken off beyond trochanter).

Head: Dark red-brown to black, white and pale yellow setose. Antennae: Light brown except for tip of style which is yellowish. Scape and pedicel white setose. Major ventral setae of pedicel project beyond level achieved by postpedicel. Basal element of style short (only slightly longer than broad). Eye to face width ratio 1.7:1. Mystax moderately well developed, white. Frons and vertex white setose. Laterally situated frontal setae extend below antennal sockets, merging with dorsal mystical setae. Occipital setae white, postoculars white except for a few (c. 10) yellowish macrosetae behind ocellar tubercle. Palps and proboscis white setose.

Thorax: Dark red-brown to black. Pronotum white and yellow setose. Mesonotum extensively setose except for narrow paramedial strips, sutural and large postsutural spots. Lateral macrosetae pale yellowish, other setae fine white (anteriorly) and yellow (posteriorly). Scutellum apruinose with moderately well-defined transverse groove; disc asetose, 12 shortish yellow-brown apical setae arranged in two groups separated by a small medial gap. Pleural setae mostly white except for orange katepimerals.Anepisternum with white setae; katatergals long, shafts more or less smooth, white. Legs: Femora dark red-brown except for orange distal tip, tibiae and tarsi orange. Claws longish, black, empodia moderately long, yellowish, pulvilli minute to absent. Wings 4.5× 1.8 mm. C orange setose basally; membrane pale brownish stained basally (including following cells—basal costal, intervenal, basal parts of costal, basal radial, basal medial and posterior cubital). Haltere yellow.

Abdomen: Dark red-brown to black; white setose. T1–3 with minute setae, except laterally, appearing asetose; T4–6 extensively covered with long reflective, reclinate and erect setae.

Genitalia: Not dissected, but visible structures conform to dissected and illustrated genitalia of a male from Serowe ( Botswana) ( Figs 33, 34 ). Epandrium greatly reduced, simple in structure, proctiger extending well beyond it. Gonocoxite with fairly long and somewhat narrow (in lateral view) external lobe tapering to broadly-rounded tip, internal lobe longish with slightly bilobed distal end. Gonostylus short, simple in structure. Hypandrium with broad, transversely oval proximal region and moderately long medial lobe distally.Medial lobe with narrow stalk-like base and bulbous apex.Aedeagus fairly slender, bent downward at about midlength, and with small, blunt tip.

Female: Similar to male but fairly variable, especially with respect to setal colour. Females possess numerous orange setae i.e. antennal setae may be orange, mystax may be largely orange, ocellars and postoculars may be mostly orange, almost entire mesonotum covered with orange setae except along posterior parts where they are yellow.

Variation: Wing length ơ 3.4–7.5 mm, ^3.5 –6.5 mm. Males generally smaller than females (measurements are skewed by a single large male). The intensity and extent of basal wing staining is variable in both sexes.

Holotype (examined): ơ ZIMBABWE: ‘Holo- / type’ [circular with red rim], ‘ Bulawayo [20°09'S: 28°35'E] / S. Rhodesia / 10.9.1922 / Rhodesia / Museum’, ‘Pres. by / Imp. Bur. Ent. / Brit. Mus. / 1931–158.’, ‘ Sisyrnodytes / brevis Maq. ’, ‘ Sisyrnodytes / subater Oldroyd / det. H. Oldroyd. 1957 / Holotype’ (BMNH). The specimen is double mounted on a cellulose strip and some green verdigris is present above and below the specimen.

Other specimens examined: BOTSWANA: 1 ơ ‘Botswana SE2226BD / Serowe. Farmer’s / Brigade. Malaise / trap. Forchhammer / ix-89’ (NMSA); 1^‘ Botswana SE2226BD / Farmer’s Brigade 5km / SE of Serowe Hillside / N slope P Forchhammer / Malaise trap 3 / 13.ix.85’ (NMSA). SOUTH AFRICA: 1^‘ N. E. Zoutp. [Soutpansberg, 22°45'S: 30°00'E] / dist. 7&8.16 / H.G. Breyer’ (NMSA); 1 ơ 2^‘ South Africa: Limpopo / Ekuthuleni (c. 7 km S. Mica) / 24°12'50''S: 30°49'16''E / 24–29.ix.2006 JGH Londt / 364m Dry Dichrostachys / Acacia Euphorbia bushveld’ (NMSA); 2 ơ 6^‘ South Africa, TVL. / Pretoria. Queens- / wood. 25.45S / 28.12E. 23.ix. / 1979 M.W. Mansell’ (SANC); 1 ơ ‘Kuruman [27°28'S: 23°26'E] / Griqualand / West / SA Museum’ ~ ‘Mus. Staff / Oct 1939 ’ (SAMC); 1^‘ Upington [28°27'S: 21°15'E]’ ~ ‘10– 12.10.1966. / S.A.M’ (SAMC); 1^‘ Kakamas [28°45'S: 20°38'E] / Cape / Oct.1951 ’ (NMSA); 1 ơ 1^‘ South Africa./ Cape Province / Kimberley [28°45'S: 24°46'E] / 17.xi.1959 / D.J. Greathead’ (BMNH); 1^‘ Sth Africa: N Cape / Canyon – 7 km N Pella / 28°59'10''S: 19°08'44''E / 28.viii.2002 JGH Londt / Ca 500m Rocky hillside’ (NMSA); 1^‘ Aggenys [Aggeneis, 29°12'S: 18°51'E] or / Bushmanland / Btw Springbok / and Pella’ ~ ‘Mus. Staff / Oct 1939 ’ (SAMC); 2 ơ 2^‘ Putsonderwater [29°14'S: 21°53'E] / N W C Prov’ ~ ‘Mus. Staff / Oct. 1939 ’ (SAMC); 1 ơ 2^‘ Niekerkshoop [29°19'S: 22°50'E] / Griqualand / West’ ~ ‘Mus Staff / Oct 1939 ’ (SAMC); 1 ơ ‘Kamieskroon [30°12'S: 17°56'E] / Namaqualand’ ~ ‘Museum Staff / Sept 1936 ’ (SAMC); 1 ơ 1^‘ Sth Africa: OFS #52 / 50km NE of Colesberg / 30°31'S: 25°33'E 1400m / Date: 28.x.1991 / Coll: J.G.H. Londt / Grass/rocky outcrops’ (NMSA); 1^‘ Sth Africa: Cape Prov / Colesberg Rocky hill / overlooking the town / 30°43'S: 25°05'E 1400m / J & H Londt 9.xii.1989 ’ (NMSA); 1^‘ Sth Africa: Cape Prov / 10km W of Williston / 15.xi.1986 3120BD / Londt & Quickelberge / 1060m Sand/Acacias’ (NMSA); 2 ơ 1^‘ S Africa: Cape #37 / 4km S of Carnarvon / 31 02'S: 22 07'E 1370m / Date: 30.xi.1990 / Whittington & Londt / A van Heerden Nat Res’ (NMSA); 1^‘ 3m. [miles] W. Hanover [31°04'S: 24°27'E] / C. Prov. S. Ar / 6:xii:1960 / Brown, Fürst / Haacke’ (SANC); 1 ơ 2^‘ Middelburg [31°29'S: 25°01'E] / Div’ ~ ‘Mus. Staff / Nov. 1935 ’ (SAMC); 4 ơ 3^‘ Murraysburg [31°57'S: 23°46'E] / Mus Staff’ ~ ‘SA Museum / Nov 1935 ’ (SAMC); 1^‘ South Africa / Cape Province / Graaf Rienet [Graaff-Reinet, 32°15'S: 24°33'E] / 19.xi.1959 / D.J. Greathead’ (BMNH); 1 ơ 1^‘ Beaufort West [32°21'S: 22°35'E] / Nieuwveldt’ ~ ‘Mus. Staff / Nov. 1935 ’ (SAMC); 1^‘ S.W. Africa: / Cape Town, / Beaufort West. / 28.xi.1933 / J. Ogilvie’ [a terrible label giving 2 different populated places that are far apart and indicating them in the wrong country!] (BMNH); 1 ơ 1^‘ Sth Africa: Cape Prov / 22km SE Graaff-Reinet / on Pearston Rd 750m / 32°27'S: 24°38'E Open / Karoo scrub/ flowers / JGH Londt 7.xii.1989 ’ (NMSA); 1^‘ Wit River Valley / Cambria area / Patensie Dist. / 6.12.67 3324DA / B&P Stuckenberg’ (NMSA); 1^‘ Capland / Willowmore [33°17'S: 23°30'E] / Nov. 3 1916 / Dr. Brauns’ (NMSA). ZIMBABWE: 1^‘ Bulawayo [20°09'S: 28°35'E] / S. Rhodesia. / 10.9.1922. / Rhodesia / Museum.’ (BMNH). Note: The Zimbabwean female, found with niveipilosus material in the BMNH, has label data identical to the holotype. Oldroyd probably failed to recognise this and to use the specimen as a paratype as both species are known from Bulawayo. Sexual dimorphism and the fact that this female is the largest I have seen (wing 6.5 mm long) may also have caused some confusion.

Distribution, phenology and biology:A fairly widely distributed species ( Fig. 42 ) found in southern Zimbabwe, eastern Botswana and the central parts of South Africa. Adults, collected from August through to December (Table 1), fly during spring and summer in areas receiving rain at that time of the year. I have collected the species in hot, dry, rocky bushveld and dry, rocky savannah biomes.

Similar species: This species is reasonably distinctive, but has some similarity to ausensis , brevis and oligotrichus .

Figures

Figs 31–38. Sisyrnodytes species, ơ terminalia in lateral and ventral aspects: (31, 32) S. oligotrichus sp. n., holotype; (33, 34) S. subater Oldroyd, 1957, Serowe; (35, 36) S. vestitus Oldroyd, 1974, Gemsbok Pan paratype; (37, 38) S. xeromyia sp. n., holotype. Scale lines = 1 mm.

Fig. 42. Distribution of Sisyrnodytes apicalis Oldroyd, 1957 (•), subater Oldroyd, 1957 (·) and xeromyia sp. n. (9).