Distega abyssinica Pasteels, 1955

Koch, Frank, Pauly, Alain, Hora, Zewdu A. & Boevé, Jean-Luc, 2015, Sawflies of Ethiopia (Hymenoptera: Argidae, Tenthredinidae), Zootaxa 4021 (1), pp. 119-155 : 147-149

Distega abyssinica Pasteels, 1955

( Figs 19 A–D, 20A–B)

Distega abyssinica Pasteels, 1955: 408 . Locus typicus: Ethiopia, Addis Ababa [Adis-Abeba].

Description. Female. Length: 7.8–8.7 mm. Head black; apical half of mandible dark reddish. Thorax black. Legs blackish except for: ventral surface of hind coxa, hind trochanter and base of hind femur white, anterior surface of fore tibia, mid tibia except for its narrow apex, base of hind tibia and base of all basitarsomeres pale. Wings conspicuously infuscate; stigma and venation black. Abdomen black, tergum 1 with two large pale lateral spots, sometimes also tergum 2 and base of tergum 3 brightened. Head parallel-sided behind eyes. Antenna 1.5–1.6 × as long as head maximum width; distal flagellomeres two times longer than broad. Eyes slightly converging below. POL: OOL = 1.0: 2.0. Postocellar area 0.7 × as long as wide; lateral furrows slightly convex towards posterior margin of head. Frontal area distinctly limited, anterior cross-ridge scarcely interrupted medially, lateral furrows slightly convex. Interantennal area with a large groove. Clypeus very slightly elongated medially, subtruncate, malar space very narrow. Vertex, frons and supraclypeal area smooth and shiny; posterior half of gena, and paraantennal area micropunctate, shiny; clypeus moderately coarsely, scattered punctate, shiny. Pubescence black, about as long as diameter of lateral ocellus. Mesoscutum scattered micropunctate, shiny; pubescence brownish to black. Abdomen smooth and shiny. Sawsheath in dorsal view narrow, in lateral view pointed apically. Lancet with about 23 serrulae ( Fig. 20 A).

Male. Body entirely black, with slight blue metallic lustre. Antenna very long ( Pasteels 1955, 407: fig. 61), 2.2–2.3 × as long as head maximum width. Penis valve as in Fig. 20 B.

The detailed description including an illustration of the penis valve is presented by Pasteels (1955).

Type material. Holotype: ♂. “ Type ” (red circle); “ Ethiopia: Addis Ababa [09°00'N 038°45'E], 8000 ft, 28.VII.–15.VIII. [19]45, K. M. Guichard. B. M. 1945-39.”; “ Type ” (red); “B. M. Type, Hym., 1-787”; “ Distega abyssinica n. sp., J. Pasteels det., 1954.”; “ Holotypus, Distega abyssinica Pasteels ♂, teste: F. Koch 2014” (red); “ Distega abyssinica Pasteels ♂, det.: F. Koch 2014” ( BMNH).

Additional Ethiopian material. Holeta, 09°04'N 038°30'E, 2450 m, with yellow pan traps, 05.VI.2012, P3671 (1 ♀), 20.VI.2012, P3672a, P3672b, P3672c (3 ♀), 21.VI.2012, P3673 (1 ♀), 26.VI.2012, P3676a (1 ♀), 26.VI.2012, P3676b (1 ♂; MFN), 04.VII.2012, P3685a (1 ♀), 05.VII.2012, P3686a (1 ♂), 10.VII.2012, P3690c (1 ♀), 20.VII.2012, P3697b (1 ♀), 31.VII.2012, P3699a (1 ♀; MFN), leg. Z. A. Hora, A. Pauly & J.-L. Boevé ( RBINS).

Distribution. Ethiopia.

Remarks. The previously unknown female of Distega abyssinica Pasteels is described here. The variability of females is apparent in the colouration of legs, which may be nearly entirely black or bicoloured (see description). The females differ from males in the ratio length of antenna to maximum width of head, and mostly in the colouration of legs. The holotype of D. abyssinica has been examined, however the genitalia are absent. No significant differences could be found between the external characters of the type and the new material. The figure of penis valve by Pasteels (1955, 407: fig. 62) is slightly different from the shape that was found in the specimens from 2012 ( Fig. 20 B). However, these differences are considered to be insignificant. Distega abyssinica is the only known Distega species with nearly entirely black body in combination with long antennae, especially in males.

Figures

FIGURE 19. Distega abyssinica. A & C, dorsal views. B & D, lateral views. A – B, male (P 3676 b), body length: 6.5 mm. C – D, females (P 3699 a & P 3672 a), body length: 8.0 mm.

FIGURE 20. Distega abyssinica. A, serrulae 10 – 12. B, penis valve (left, lateral view).