Dogonia saegeri Oldroyd, 1970

Londt, Jason G. H., 2008, A review of the Afrotropical genus Dogonia Oldroyd, 1970, with new synonymy (Diptera: Asilidae: Stenopogoninae), African Invertebrates 49 (1), pp. 123-123 : 125-127

Dogonia saegeri Oldroyd, 1970

Figs 1–8

Dogonia saegeri Oldroyd, 1970: 269–270 , figs 42 (head in lateral view and detail of antenna), 43 (♂ terminalia), 44 (head in anterior view).

Dogonia nigra Oldroyd, 1970: 270–271 , fig. 41 (♂ terminalia). Syn. n.

Oldroyd (1970) provided reasonable descriptions of both saegeri and nigra . He distinguished nigra from saegeri ‘by its black colour, and by the different shape of the male terminalia’. However, even a superficial look at the material shows that there is considerable variation in colour. For example, four of the specimens (including the type of nigra ) have abdomens that could be described as ‘black’ while the other four are somewhat ‘orange’. Additionally, Oldroyd did not excise and macerate the male terminalia, but merely produced somewhat diagrammatic illustrations of them (fig. 41 – nigra , and fig. 43 – saegeri ) based on the dry structures. Having now removed the terminalia and macerated them in potassium hydroxide I can report that the unique nigra holotype is essentially similar to the males of saegeri . I need to record that I find it difficult to interpret Oldroyd’s fig. 41 as the macerated structures bear little resemblance to the published diagram. In view of my findings, I confidently synonymise nigra with saegeri . This action effectively makes Dogonia a monotypic genus.

The following brief redescription, which should be read in conjunction with Oldroyd’s descriptions, is based on the examination of all the available material and highlights some of the variation seen. Unfortunately, most of the specimens are not in particularly good condition and all have parts that are either broken or missing.

Description:

Head: Dark red-brown, gold-silver pruinose, but weakly so on face below antennal sockets. Antennal scape only slightly longer than pedicel, style well-developed with terminal spine. Face slightly protruding in ventral half; mystax shiny whitish with a few black setae laterally [1♀entirely whitish], covering facial tubercle. Occipital macrosetae absent, fine setae whitish. Eye:face width ratio 1.03–1.17:1 (mean 1.12, i.e. eye slightly wider than face). Palpus 2-segmented, proboscis elongate and not markedly broader basally.

Thorax: Mesonotum dark red-brown with lateral parts, including postpronotal and postalar lobes, commonly orange-brown to orange [some individuals mostly dark redbrown laterally]; gold-silver pruinose especially laterally; macrosetae poorly developed, black, general setation predominantly black except on postpronotal and postalar lobes where setae are yellowish. Pleura patchy dark red-brown and orange-brown [intensity of orange-brown areas is variable], setae fairly sparse and usually yellowish except for katatergal setae which are long, predominantly black in males and yellowish in females. Anatergal setae longish, yellowish. Scutellum dark red-brown with fine black setae. Legs: Ranging from prothoracic legs orange-brown, metathoracic legs brown-orange, mesothoracic legs intermediate to all legs dark red-brown [i.e. intensity of colour is variable]; macrosetae black, fine setulae pale yellowish. Halters usually yellowish to pale orange [may be slightly brownish]. Wing ( Fig. 1 ): Fairly uniformly dark brown to blackish stained, but may be slightly weaker stained in central parts of distal cells enclosed by costal vein; uniformly blackish microtrichose. Smallest wing 7.4× 3.8 mm ( nigra holotype), largest 10.7× 4.5 mm (a ♀paratype), mean 9.3× 3.9 mm.

Abdomen: Terga range from orange through to black, largely shiny apruinose but T1–7 silvery pruinose laterally (extent of pruinescence gradually diminishing posteriorly), discal macrosetae not evident, general tergal setation black, mostly laterally situated [variation in degree of development is evident and some specimens have some yellowish setae as well]. Sterna similarly variable in colour, but apruinose and usually almost entirely asetose. Membranes binding terga with sterna blackish. Genitalia usually slightly darker in colour than more anteriorly situated segments.

Male terminalia ( Figs 2–8 ): Epandrium in lateral view similar in length to hypandrium, and gonocoxite projecting beyond levels attained by either epandrium or hypandrium. Epandrium in dorsal view deeply incised medially, the two lobes just touching proximally. Proctiger bilobed and fairly broad in dorsal view. Gonocoxite subtriangular in lateral view with small dorsodistal lobe-like projection and finger-like dorsomedial projection that largely hidden from view, but more easily seen when viewing genitalia dorsally or ventrally. Gonostylus also finger-like but with upturned, somewhat pointed tip. Hypandrium subtriangular when viewed ventrally; tip somewhat ridged ventromedially and with narrowly rounded apex. Aedeagus proximally bulbous, prongs small, converging to acutely pointed tip.

Female terminalia ( Fig. 9 ): Epigynium unremarkable. Hypogynium broader than long, medially incised to almost half its length. Acanthophorites each bearing six variously developed macrosetae.

Material examined: DRC: ♂ holotype (of saegeri ), ‘HOLOTYPUS’ [orange], ‘ Congo belge, P.N.G. [Garamba National Park, 04°10'N: 29°30'E] / Miss. H. De Saeger / AKAM [?], 24-III-1950 / Réc. H. De Saeger. 327’, ‘ Dogonia / staegeri [sic] Oldroyd / H. Oldroyd det., 1965 / HOLOTYPE’ (MRAC); 1♀paratype, ‘Para- / type’ [orange], ‘ Congo belge, P.N.G. / Miss. H. De Saeger / AKAM, 24-III-1950 / Réc. H. De Saeger. 327’, ‘ Dogonia / saegeri Oldroyd / det. H. Oldroyd 1966 / PARATYPE’ (IRSB); 1 ♂ 2♀paratypes, ‘PARATYPUS’ [orange], ‘ Congo belge, P.N.G. / Miss. H. De Saeger / Mt. Ndogo [?], 15.III.1950 / Réc. H. De Saeger. 305’, ‘ Dogonia / staegeri Oldroyd / H. Oldroyd det., 1965 / PARATYPE’ (MRAC); 1♀paratype, ‘Para- / type’ [orange], ‘ Congo belge, P.N.G. / Miss. H. De Saeger / Mt. Ndogo, 15.III.1950 / Réc. H. De Saeger. 305’, ‘ Dogonia / saegeri Oldroyd / det. H. Oldroyd 1966 / PARATYPE’ (IRSB); 1♀paratype, ‘Para- / type’ [orange], ‘ Congo Belge, P. N.G. / Miss. H. De Saeger / II/fe/18 [?], 31-III-1952 / H. De Saeger. 3262’, ‘ Dogonia / saegeri Oldroyd / det. H. Oldroyd 1966 / PARATYPE’ (IRSB); ♂ holotype (of nigra ), ‘HOLOTYPUS’ [orange], ‘ Congo belge, P.N.G. [Garamba National Park] / Miss. H. De Saeger / I/a/1 [?], 13-III-1950 / Réc. H. De Saeger. 301’, ‘ Dogonia / nigra Oldroyd / H. Oldroyd det., 1965 / HOLOTYPE’ (MRAC).

Note: While The Garamba National Park (G.N.P.) is to be found in gazetteers, I have not been able to locate the precise positions of either Akam or Mt Ndogo within this park. Two specimens do not possess locality information other than ‘P.G.N.’ but instead have codes (i.e. II/fe/18 and I/a/1 respectively) that I am unable to decipher.

Figures

Fig. 1. Right wing of Dogonia saegeri Oldroyd, ^paratype, Akam, DRC.

Figs 2–9. Dogonia saegeri Oldroyd, Mt Ndogo, DRC: (2–8) _ terminalia: (2–5) paratype: (2) lateral, (3) dorsal, (4) ventral, (5) detail of aedeagus; (6–8) D. nigra Oldroyd, holotype: (6) lateral, (7) dorsal, (8) ventral; (9) ^terminalia, paratype. Scale line = 1 mm.