Synolcus acrobaptus ( Wiedemann, 1828 )

Londt, Jason G. H., 2012, The genus Synolcus Loew, 1858, with descriptions of new species (Diptera: Asilidae), African Invertebrates 53 (2), pp. 661-661 : 665-670

Synolcus acrobaptus ( Wiedemann, 1828)

Figs 2 , 15–21 , 76 , 88

Asilus acrobaptus: Wiedemann 1828: 449 .

Asilus incisuralis Macquart, 1838: 140 . Syn. n.

Synolcus signatus Loew, 1858: 362 ; 1860: 148–149, figs 1a (♂ gen.), 1b (♂ wing), 1c (head), 2a (♀ wing), 2b (♀ gen.); Kertész 1909: 282 (catalogue); Engel 1927: 145; Hull 1962: 526; Oldroyd 1974: 165; 1980: 346 (catalogue); Londt 1980: 30–32.

Synolcus acrobaptus: Kertész 1909: 282 (catalogue); Engel 1927: 145–146, figs 8 (♂ gen.), 8a (♀ gen.); Hull 1962: 526, figs 724 (wing), 1459, 1469 (head); Oldroyd 1974: 165, fig. 161 (wing); 1980: 346 (catalogue); Londt 1980: 25–27, figs 2 (wing), 8–10 (♂ gen.), 11 (♀ gen.); 1990: 2, 9.

Notes on synonymies:

Asilus incisuralis Macquart, 1838

Oldroyd (1980), without explanation, catalogued Asilus incisuralis Macquart, 1838 as a valid Synolcus . This species had never before been associated with the genus. Unfortunately efforts to trace Macquart’s material, believed to be in the Museum National d’Histoire Naturelle, Paris, France, proved unsuccessful. Macquart’s (1838:140) description of Asilus incisuralis is brief and is reproduced below as it appears in the original publication.

13. ASILUS INCISURALIS, Nob.

Ater. Abdomine basi, incisurisque albidis. Pedibus nigris.

Alis fuscanis, dilatatis ♂.

Long. 5 l. ♂

Face à duvet blanchâtre; moustache noire en-dessus, blanche en-

dessous. Barbe blanche. Thorax cendré, à larges bandes noires.

Abdomen noir; les deux premiers segments à léger duvet blanc; les autres à incisions blanches. Pieds noirs; jambs un peu testacées.

Ailes dilatées au bord extérieur, gaufrées, un peu brunâtres, à base et centre clairs.

Nous rapportons à la meme espéce un individu ♀ qui en différe par les jambs testacies, à extrémité noire; les ailes ne sont pas dilatées et l’espace clair est plus grand.

L’un et l’autre sont de Cap. Collection de M. Serville.

Although Macquart’s description is not detailed enough to allow definite conclusions to be formulated concerning the generic placement of the species it appears to support placement within Synolcus . If it is indeed a Synolcus , the small size (length c. 10.5 mm) and mystacal coloration would suggest an affinity with the acrobaptus species-group which occurs in the region once referred to as ‘Cap’ (= Cape). However, Macquart described the wing as dilated, and while many Synolcus have dilated wings this is not an obvious feature of species in the acrobaptus group whose wings are usually only slightly dilated.

In the interests of taxonomic stability I here suggest that Asilus incisuralis Macquart, 1838 should be considered a synonym of Synolcus acrobaptus ( Wiedemann, 1828) until proved otherwise.

Synolcus signatus Loew, 1858

Londt (1980), in discussing the synonymy of signatus with acrobaptus , tentatively repositioned signatus within the synonym of dubius because the illustrations provided by Loew (1860) were clearly not depictions of typical acrobaptus , but were instead far more representative of dubius . I suggested that Loew might have mislabelled his illustrations and that they actually depicted his other 1858 species, tenuiventris (subsequently synonymised with dubius ). Now that I have studied good photographs of Loew’s types of both signatus and tenuiventris , housed in the NHRS, I can report with certainty that Loew did indeed mislabel his illustrations. Loew’s signatus type clearly represents acrobaptus and his illustrations depict well the wings, head and genitalia of tenuiventris . My decision to tentatively place signatus in the synonymy of dubius was therefore incorrect. However, there is another matter that requires mention. Loew (1858) gives the provenance of signatus as ‘Caffraria (Wahlb.)’, but in 1860 he states ‘(Cap, Victorin.)’. The NHRS female bears Victorin’s name and ‘Cap. B. Spei’ (Cape of Good Hope) while the male is merely labelled with numbers that may refer to Wahlberg’s collecting activities in ‘Caffraria’ (now understood to be in the eastern parts of southern Africa). The significance of Loew’s two, apparently conflicting citations is not known.

Redescription:

Male.

Head: Dark red-brown to blackish, strongly silver pruinose, white and black setose. Antenna: Dark red­brown to blackish, fine silver­gray pruinose, scape and pedicel black setose, postpedicel may have some black setae dorsally; mean segmental ratios (n =5) 1:0.9:1.6:1.5 (0.3:1.1:0.1), i.e. pedicel slightly shorter than scape, postpedicel about 1.5 length of scape, stylus about as long as postpedicel. Face: Blackish, strongly silver pruinose. Mystax mostly white with a variable number of black setae medially (rarely absent), setae better developed ventrally. Frons and vertex: Blackish, weakly silver-gray pruinose, frons white and black setose laterally (rarely entirely white), ocellar tubercle black setose (rarely white). Occiput: Blackish, strongly silver pruinose, black (dorsally) and white (centrally and ventrally) setose (rarely entirely white).

Thorax: Dark red-brown to blackish, silver and red-gold pruinose, black, pale yellow and white setose. Prothorax: Dark red-brown to blackish, silver pruinose, white setose. Mesonotum: Dark red-brown to blackish, silver pruinose with red-gold pruinose median band and lateral patches (may also be fairly uniformly red-gold pruinose), macrosetae uniformly black or mixed black and pale yellow, minor setae short blackish (mainly anteriorly) and longish white (mainly posteriorly). Macrosetae (uniform black or mixed black and pale yellow): acr and dc moderately developed posterior of transverse suture only, 2 npl, 2 spal (1 strong, 1 weak), 1–2 pal (1 strong, 1 absent or weak). Scutellum: Dark red-brown to blackish, silvery pruinose, disc white or mixed black and white setose, 1 pair black or pale yellow apical macrosetae. Pleura: Uniform dark red-brown to black, silver to silver-gold pruinose, weakly white and pale yellow (ktg) setose. Legs: Cx dark red-brown to black, silver pruinose, white setose; cx 3 with 2–3 lateral macrosetae. Tro dark red-brown, largely apruinose, weakly white setose. Fem uniform dark red-brown to black, major setae mostly pale yellow (few black), minor setae long or short white. Tib uniform brown, major setae black and pale yellow, minor setae white. Tar dark red-brown, major and minor setae mostly black (may be a few pale yellow major setae). Wing ( Fig. 2 ): Veins mostly dark red-brown, anterior veins more orange-brown proximally, membrane usually transparent, but may be pale yellowish, wing tip commonly dark stained. Cell sc with sc–r. Cells r 1 and r 2+3 slightly expanded and displaying corrugations. Wing length × breadth (mean, n= 10) 6.6 (6.4–7.6) × 2.3 (1.8–2.8) mm. Haltere: Pale yellow with pale brownish distal and proximal ends.

Abdomen: Dark red-brown to black, silver and dull reddish pruinose, black and white setose. T1 fairly uniformly silver pruinose, 3–4 white macrosetae laterally accompanied by many white setae, medially short black setose. T2–8 mostly silver pruinose but usually darker in appearance anteromedially with a dull reddish pruinescence, setae mostly white laterally and posterolaterally (including c. 3 macrosetae), mostly short black anteromedially. S as T but uniformly silver pruinose, white setose.

Terminalia ( Figs 15–21 ): Epand in lateral view ( Fig. 15 ) at least 3 times as long as deep, with narrowly rounded distal tip; epand lobes in dorsal view narrowly separated proximally. S8 well-developed, thickly setose along posterior margin and projecting distally as a somewhat trifurcate structure (in ventral view, Fig. 17 ) that largely hides from view both hypd and goncx. Central prong of S8 projecting distally as a dorsally directed finger­like lobe ( Fig. 17 ) that demonstrates geographical variation ( Figs 20, 21 ), the tip becoming broader distally in the eastern parts of the distribution. Hypd poorly developed. Gonst in lateral view as in Fig. 18 . Aed S-shaped distally ( Fig. 19 ).

Female: Essentially similar to male. Wing length × breadth (mean, n=10) 6.6 (4.7–8.3) × 2.1 (1.5–2.8) mm (size and range almost identical to ♂). Terminalia ( Fig. 76 ): Ovipositor laterally compressed, knife-like, elongate (almost 3 times as long as deep).

Material examined: SOUTH AFRICA: 1♀ Nieuwoudtville, Wild Flower Res. 3119AC, 690 m, 16.xi.1986 , Londt & Quickelberge; 1♂ 5♀ Cape Town, Table Mountain near Cable Way (Bottom) Station , 3318CD, 25.iii.1979 , Londt; 4♂ 2♀ Gydo Mt. 24 km NE Prince Alfred Hamlet, 3319AB, 1150 m, 21.xi.1986 , Londt & Quickelberge, rocky area/ Proteas; 2♀ Worcester, Karoo Botanic Gardens , 3319CB [33°36'57"S 19°27'09"E], 30.xii.1982 – 6.i.1983 , Miller, Malaise trap; 3♂ 2♀ same date but 1–2.i.1983, Miller & Stabbins; 2♂ 1♀ Jan de Boers , 18 km NE Touws River, 3320AC, 1000 m, 20.xi.1986 , Londt & Quickelberge, rocky area nr fields; 2♂ 1♀ Cogman’s Kloof, Ashton­Montagu Road , 3320CC, 11.i.1983 , Stabbins & Miller, along river; 3♂ 2♀ Oukloof , 3 km S Prince Albert, 3322AA, 10.xi.1986 , Londt & Quickelberge, sand/ Acacias; 3♀ Meiringspoort , 3322BC, 11–12.xii.1979 , Londt & Stuckenberg, rocky hillside & stream edge; 1♀ Diepkloof c. 20 km E De Rust, 3322BD, 12.xii.1979 , Londt & Stuckenberg, dry rocky hillside & stream; 2♂ 3♀ Uniondale , 3323CA, 12.xii.1979 , Londt & Stuckenberg, steep hillside macchia; 1♀ Brenton­on­Sea , 3423AA, 10.xii.1979 , Londt & Stuckenberg, dune & hillside vegetation; 2♂ Doring River Waterfall , 10 km NE Nieuwoudtville, 31°19.18'S 19°07.04'E, 660 m, 16–17.xi.2008 , Londt, rocky riverine bush; 1♂ Akkerendam Nat. Res. , 31°26'54"S 19°46'27"E, 1050 m, 5–6.ix.2002 , Londt, Karoo bushes W slope of small hill; 2♂ Bulhoek, Klaver – Clanwilliam [32°01'S 18°47'E], x.1950 , Mus. Exp. ( SAMC) ; 1♀ Bulshoek, Clanwilliam [32°01'S 18°47'E], 12­56 [xii.1956], SAM [South African Museum] ( SAMC) ; 1♀ Hillside behind Motel , 6 km SW Clanwilliam, 32°11'S 18°53'E, 200m, 1.xi.1991 , Londt; 4♀ Urquhart Park Caravan Park, Graaff­Reinet , 32°15'S 24°33'E, 4–6.xii.1988 , Londt, riverine veget. sandy ground; 4♂ Karoo National Park , 32°19'S 22°30'E, 13.xi.1993 , Koch ( ZMHB); 7♂ 3♀ Jamaka Farm , 32°20'S 19°01'E, 2–7.xii.2007 , Koch ( ZMHB); 1♀ Clanwilliam District, Algeria Forestry [32°22'S 19°04'E], 4–10.iii.1969 , Potgieter & Strydom; 1♂ 1♀ Valley nr Observatory , 15 km E Sutherland, 32°23'S 20°48'E, 1600 m, 26.xi.1990 , Whittington & Londt; 3♂ 2♀ Olifants River, between Citrusdal & Clanwilliam [c. 32°24'S 18°57'E], x–xi.1931 , Mus. Staff ( SAMC); 2♂ 2♀ Ouberg Pass, SE Touws River [32°25'S 20°21'E], xii.1962 , SAM ( SAMC); 1♂ Citrusdal [32°35'S 19°01'E], xi.1948 , Mus. Exp. ( SAMC); 1? Piketberg [32°54'S 18°46'E], i.1940 , Mus. Staff ( SAMC); 5♂ 5♀ Gonnemanskraal , N Jacobsbaai, 32°57'14"S 17°53'07"E, 0–10 m, 9–10.xi.2002 , Londt, dune veget. & rocks; 1♀ same data but 21–26.xii.2002 , Londt, dune sand & vegetation; 1♂ 1♀ Koup Siding [33°07'S 21°16'E], xi.1939 , Mus. Staff ( SAMC); 2♂ Constable [33°15'S 20°19'E], ii.1958 ( SAMC) ; 2♂ Near Floriskraal dam, 19 km SE Laingsburg, 33°17'S 20°57'E, 700 m, 25.xi.1990 , Whittington & Londt; 1♂ Witteberge c. 7 km E Constable, 33°17'54"S 20°19'24"E, 870 m, 12.xi.1998 , Londt, sandy soil/succulents; 1♂ 1♀ Verkeerde Vlei [33°20'S 19°20'E], xii.1962 , SAM ( SAMC); 1?[♀] Witzenberg Valley [33°20'S 19°30'E], 3000 ft [c. 914 m], 19.i.1921 , Turner ( BMNH); 1? [♀] Ceres District, Witzenberg Valley , 3500 ft [c. 1067m], 21–23 xii.1920 , Turner ( BMNH) ; 1♀ Touws River [33°20'S 20°02'E], xii.66 [1966], Mills; 1♂ 9♀ Hondewater , 18mi. E Touws River [33°20'S 20°02'E], xii.1962 , SAM ( SAMC); 1♂ 1♀ Seweweekspoort [33°22'S 21°25'E], 4–6.xii.1968 , Potgieter & Jones; 1♂ 2? Malmesbury [33°27'S 18°44'E], 15.ii.1961 , SAM Exped. ( SAMC); 1♀ Hex River [33°29'S 19°35'E], xi.1884 ( ZSMC) ; 1♀ Bloutoring Station, 30m E Touws River [33°30'S 20°14'E], xii.1962 , SAM ( SAMC); 1♀ Worcester [33°36'S 19°34'E], i.1934 , Turner ( BMNH); 1♂ 1♀ Paarl Mt. [33°44'S 18°56'E], ii.1932 , Mackie ( BMNH); 1♀ Montagu [33°44'S 20°07'E], xi.1919 , Lightfoot ( SAMC); 4♂ 2♀ Robertson District, Dassiesberg [33°48'S 19°53'E], i.1936 , Mus. Staff ( SAMC) ; 1♂ Algoa Bay [Port Elizabeth, 33°58'S 25°35'E], Brauns ( ZSMC) ; 1♂ 1♀ 1? Cape Town [33°56'S 18°23'E], 1913, Peringuey ( SAMC) ; 1♂ Cape Town ( ZSMC) ; 1♂ 1♀ Lion’s Head Nature Res, Kloofnek area , 33°56'29"S 18°23'10"E, 220 m, 14.xii.2004 , Londt, fynbos stony path; 1♂ Stellenbosch [33°56'S 18°51'E], iv.1964 ,

Loubser; 1♀ Stellenbosch , iii.1964, Loubser ; 1♀ Stellenbosch , x.1964, Loubser ; 1♀ Stellenbosch , i.1950, Schoeman ; 1♂ Swellendam District , Tradouw Pass [33°57'S 20°42'E], xi.1925, Mus. Exped. ( SAMC) ; 1♂ 15 km S Villiersdorp [33°59'S 19°17'E], 28.xii.1983, Brothers ; 4♂ 1♀ 1? Bontebok National Park , 34°04'S 20°28'E], 2–3.i.1993, Koch ( ZMHB) ; 1♀ Kommetjie , hill overlooking town, 34°08'S 18°19'E, 13.xii.1988, Londt, macchia sandy ground & rocks ; 2♀ Mossel Bay [34°11'S 22°08'E], 1.xii.1938, Turner ( BMNH) ; 1♂ ‘ Capland , Bergius’, 2228 [?] ( ZMHB, with red ‘ Typus’ label) .

Type specimens: While I have not handled Loew’s type specimens of signatus , I have studied a series of photographs of both a male type labelled ‘294’, ‘R’, ‘65’ and a female type labelled ‘295’, ‘24’, ‘Cap. B. / Spei.’, ‘Victo- / rin.’ (NHRS), which clearly show important details of both specimens, especially their wings and genitalia. I am, therefore, confident that these specimens truly represents acrobaptus .

Distribution, phenology and biology: Restricted to, but widely distributed within the south-western parts of South Africa ( Fig. 88 ), being recorded from the Northern Cape, Western Cape and Eastern Cape provinces.Adults fly from September through to April (Table 1). Label data and personal experience indicate that the flies rest on low vegetation and on the ground (sandy and rocky).

Figures

Figs 2–14. Synolcus species,♂ wing venation:(2) S.acrobaptus (Wiedemann, 1828) (Gydo); (3) S.amnoni Londt, 1990 (Nkhandla); (4) S. argentius Londt, 1990 (5 km NE Grootderm); (5) S.armstrongi sp.n. (Karkloof paratype); (6) S. aurulentus Engel, 1929 (Outeniqua); (7) S. dubius (Macquart, 1846) (Ntumeni); (8) S. griseus Engel, 1927 (Entabeni); (9) S. macrocercus sp. n. (Middelpos paratype); (10) S. malawi Londt, 1990 (Lichenya paratype); (11) S. minor (Bromley, 1947) (Melmoth); (12) S. namibiensis sp. n. (Ai-Ais paratype); (13) S. spinosus Londt, 1980 (Gladdespruit paratype); (14) S. ukhahlamba sp. n. (Monks Cowl holotype).

Figs 15–21. Synolcus acrobaptus (Wiedemann, 1828), male genitalia: (15–19) lateral, dorsal, ventral, gonostylus and aedeagal tip (Cape Town); (20, 21) variation in S8 shape: (20) Touws River male; (21) Prince Albert male. Scale line 1 mm.

Figs 76–86. Synolcus species, ovipositor: (76) S. acrobaptus (Wiedemann, 1828) (Cape Town); (77) S. argentius Londt, 1990 (5 km NE Grootderm, redrawn from Londt 1990); (78) S. armstrongi sp. n. (Karkloof paratype);(79) S.aurulentus Engel,1929 (Knysna Forest, redrawn from Londt 1980); (80) S. dubius (Macquart, 1846) (Coffee Bay, redrawn from Londt 1980); (81) S. grieseus Engel, 1927 (Entabeni,redrawn from Londt 1980); (82) S.macrocercus sp.n.(Worcester paratype);(83) S. minor (Bromley, 1947) (Ngome, redrawn from Londt 1990); (84) S. namibiensis sp. n. (Ai-Ais paratype); (85) S. spinosus Londt, 1980 (Gladdespruit paratype, from Londt 1980); (86) S. ukhahlamba sp. n. (Injasuti paratype). Scale lines 1 mm.

Fig.88.The distributions of species in the Synolcus acrobaptus species-group (excluding S. malawi Londt, 1990):S.acrobaptus(Wiedemann,1828) – squares,S.argentius Londt,1990 – circles,S.macrocercus sp. n. – triangles, S. namibiensis sp. n. – diamonds.