Sepedon (Sepedomyia) nasuta Verbeke, 1950

Knutson, Lloyd V., Deeming, John C. & Ebejer, Martin J., 2018, The Snail-killing Flies (Diptera: Sciomyzidae) of West Africa, Zootaxa 4483 (1), pp. 67-100 : 87-89

Sepedon (Sepedomyia) nasuta Verbeke, 1950

(Figs 26, 31–34)

Sepedomyia Verbeke, 1950 . (as subgenus by Steyskal 1973).

Type species: Sepedomyia nasuta Verbeke, 1950 . By original designation. filiformis Verbeke, 1950 (Sepedomyia) DEMOCRATIC REPUBLIC OF CONGO. Synonymy by Steyskal & Verbeke 1956: 1.

Steyskal (1973) included Sepedomyia within Sepedon in his key, noting that characters used to separate Sepedomyia from Sepedon were “very doubtfully more than subgenerically distinct.” Sepedomyia was proposed as a new genus for the type species (based on six males) and S. filiformis Verbeke, 1950 (based on four females) (= S. nasuta , Democratic Republic of Congo, synonymy by Steyskal & Verbeke (1956), primarily on the basis of an anteriorly more-or-less angulate scutum; elongate scape (at least 2/3 as long as postpedicel); postpronotal seta present, but setulae-like, presutural seta weak to strong, epandrium cape-like, tergite 7 elongate. Verbeke (1950) presented a lateral view of the postabdomen with surstyli and a ventral view of the inner copulatory apparatus. The postabdomen is figured herein (Figs 31, 32) with ventral (Fig. 33) and lateral (Fig. 34) views of the inner copulatory apparatus. Subsequently Verbeke (1962b) described Sepedomyia alaotra from Madagascar, based on two females, and S. nasuta was recorded from South Africa (Pondoland: Steyskal & Verbeke 1956), Uganda & Tanzania ( Knutson 1968) and S.W. Africa, Kaokoveld [ Namibia] ( Verbeke 1961). Important features not mentioned by Verbeke (1950) are described below.

Tergite 1 with elongate, bladelike internal phragma extending from anterolateral corner at an angle to anterior margin of unusually long tergite 2, with which tergite 1 is fused. Sternite 4 with a bare, triangular plate with pair of C-shaped sclerotized plates laterally, strongly setose on apical ½. Sternite 5 a pair of weakly sclerotized rounded plates. Surstylus a quadrate lobe tapered on external margin apically; a few fine, short black setulae on outer surface of apical ½, in lateral view straight, with a triangular base in cross-section, external margin triangularly produced. No bacilliform sclerite. Ejaculatory apodeme not seen; no cochleate vesicle. Aedeagal apodeme short, straight. Hypandrium massive, symmetrical, with a pair of large, apically rounded ventral apodemes. Basiphallus a conical tube narrowed apically. Elongate-oval posterior gonopod near base of basiphallus. Distiphallus a complex tubular structure surrounding basiphallus, in lateral view with 3 apical processes; dorsally a wing-shaped plate, median quadrate plate and ventrally a median tubelike acrophallus.

References to figures: Verbeke 1950 (postabdomen, aedeagus).

Holotype: ♂, DEMOCRATIC REPUBLIC OF CONGO, Rwindi , 1000m, 26.xi.1934, Mission G.F. de Witte, ( MRACT) . Seen in IRSNB, Cabinet No. 41, “Parc National Albert”, Box No. 1 by Knutson in 1978. Paratypes: 5♂, DEMOCRATIC REPUBLIC OF CONGO, Rwindi, Katanda , 950m; s . Lac. Edouard, riv. Rwindi, 1000m, ( IRSNB and MRACT) seen in IRSNB, Cabinet No. 41, “Parc National Albert”, Box No. 1 by Knutson in 1978.

WEST AFRICA: NIGERIA: Zaria , Samaru, m. v. trap , 1♂, 29.i.1969; 1♀, 20.xi.1967; 2♀, 1.iii.1968; 1♀, 31.iii.1968 ( IARS) ; same locality, 1♀, 11.ii.1967; 1♀, 11.i.1968; 1♂, 5.ii.1968 ( USNM); nr. Mokwa, Zugurma, kurmi (Hausa word for a pocket of equatorial woodland in surrounding savannah), 1♂, 26.xi.1971 ( USNM) (all collected by Deeming) . IVORY COAST: Lamto , Bandama, 1♀, 22.ii.1971, D. Lachaise ( MNHNP).

MAURITANIA: Basse-Casaurance , Djibélor, 1♂, 8.iv.1980, J. Etienne ( MNHNP).

Published records. DEMOCRATIC REPUBLIC OF CONGO ( Verbeke 1950, 1961 (incl. S. filiformis ) 1963); SOUTH AFRICA (Pondoland) ( Steyskal & Verbeke 1956); NAMIBIA (as S.W. Africa ( Verbeke 1961); UGANDA and TANZANIA ( Knutson 1968).

Other new records: ZIMBABWE (as RHODESIA): Salisbury , 1♂, xii.1929, A. Cuthbertson ( USNM) ; DEMOCRATIC REPUBLIC OF CONGO: Musosa , 1♂, xi.1939, H.J. Brédo ( IRSNB) ; ANGOLA: (A 42) Rogadas , 1♀, 30.iii.1972, B. Cogan ( NHMUK) ; BOTSWANA: (B7) Kuke Pan , 20°59ʹS, 22°25ʹE, 1♂, 14–15.iv.1972; (B22) R. Semowane, 20°25ʹS, 26°23ʹE, 1♀, 23–24.iv.1972, (both B. Cogan, NHMUK) ; MALAWI: Limbe, 1♂ 1♀, ix.1916, R.C. Wood ( NHMUK) .

Biology. Unknown.

Figures

PLATE 1. Figs 1–4, Colobaea occidentalis sp. n. ♂, 1—head, frontal View, 2—thorax, dorsal View, 3—hypopygium, lateroVentral View, posterior surstylus not shown, 4—head, lateral View. AbbreVations: Ae—aedeagus, AeA—aedeagal apodeme, As—anterior surstylus, Bp—basiphallus, C—cercus, CV—cochleate Vesicle, Dp—distiphallus, EjA—ejaculatory apodeme, Ep—epiphallus, F—aedeagal filament, Hy—hypandrium, Ps—posterior surstylus.