Cassida namibiensis Borowiec, 2005

Borowiec, Lech & Świętojańska, Jolanta, 2022, A monograph of the Afrotropical Cassidinae (Coleoptera: Chrysomelidae). Part 6. Revision of the tribe Cassidini 3, the genus Cassida L., Zootaxa 5171 (1), pp. 1-250 : 112-113

Cassida namibiensis Borowiec, 2005

( figs. 27 , 204–206 )

Cassida namibiensis Borowiec, 2005: 119 .

Description. L: 4.20–4.50 mm, W: 3.00–3.10 mm, Lp: 1.50–1.70 mm, Wp: 2.60–2.70 mm, L/W: 1.39–1.45, Wp/ Lp: 1.56–1.73. Body oval, almost parallel sided ( figs. 204, 205 ).

Pronotum yellow. Elytra yellow, in holotype and one of the paratypes postscutellar elevation with small brown spot, and punctures of elytra with dark brown centre or/and with narrow brown areola. In third row areolae of three punctures in 1/3 and slightly behind half length of row joined and form small spot ( fig. 205 ). In the second paratype elytra uniformly yellow ( fig. 204 ). Clypeus yellow with black basal corners, labrum brown. Thorax mostly black, apex of prosternal process yellowish, lateral plates partly brown. Abdomen in holotype mostly black with yellow margin, in both paratypes uniformly yellow. Legs yellow, coxae from yellow to brown. Antennae uniformly yellow, or only last two segments infuscate to brown.

Pronotum elliptical, with maximum width at basal 1/3 length, sides slightly unevenly rounded but not angulate. Anterior margin almost semicircular and pronotum looks more rounded anteriorly than in any other species of Cassida lacrymosa group. Disc moderately convex, indistinctly bordered from explanate margin, with indistinctly separated area above head. Surface of disc very shallowly and sparsely punctate, appears slightly opaque. Explanate margin broad, with honeycomb structure, impunctate, surface slightly opaque.

Scutellum triangular, impunctate, without transverse rows or wrinkles. Base of elytra only slightly wider than pronotum, emargination between pronotum and elytra shallow, shallowest within Cassida lacrymosa group. Humeri moderately protruding anterad, angulate. Anterior margin of elytron shallowly emarginate with small, black crenulation. Disc in profile moderately convex, with top of convexity in postscutellar area, behind postscutellar elevation slightly depressed ( fig. 206 ). Postscutellar impressions distinct, bordered externally by slightly elevated second interval, postscutellar area with distinct H–shaped elevation. Punctation of disc regular, coarse and dense, but smaller and sparser than in any species of Cassida lacrymosa group. Distance between punctures in rows mostly as wide as diameter of puncture. Intervals flat, mostly twice narrower than rows. Marginal row distinct, its punctures as coarse as or slightly coarser than punctures in submarginal row. Marginal interval broad, as wide as two marginal rows and marginal interval together. Explanate margin of elytra moderately declivous, broad, slightly wider than 1/5 width of disc. Surface of explanate margin shallowly, sparsely punctate, appears mostly regular, punctures smaller than on disc.

Head moderately broad, eyes large, gena very short. Clypeus almost as wide as long, with distinct clypeal lines converging in triangle, surface of clypeus shiny, glabrous, with a few shallow punctures. Labrum shallowly emarginate to 1/6 length. Antennae stout, segments 8–10 slightly longer than wide. Length ratio of antennal segments: 100:50:75:54:50:42:42:33:38:38:88, segment 3 approximately 1.5 times as long as segment 2, and 1.4 times as long as segment 4.

Prosternal process moderately broad in the middle, strongly expanded apically, sulcate along sides, expanded plate elevated, with few coarse punctures.

Claws with basal tooth.

Distribution. Namibia ( fig. 27 ).

Remarks. A member of the Cassida lacrymosa species–group. With C. eluta it is one of the smallest and the most elongate species of the group with length below 4.6 mm and L/W: 1.39–1.45. Its immaculate pronotal disc and predominantly yellow elytra with a scarce pattern of small brown spots place C. natalensis close to C. voiensis and especially to C. eluta . The first species differs in the elytral pattern reduced only to dark, reddish brown centres of punctures of elytral sides with the central part of the disc without pattern except for a spot on the postscutellar elevation and a few very small reddish brown spots in the posterior half of the disc, base of elytra slightly wider than pronotum and sides of elytra slightly more rounded (figs. 207, 208). The second species differs in slightly coarser elytral punctation, with distance between punctures in lateral rows mostly smaller than puncture diameter and sides of elytra slightly more rounded; both species are broadly separated geographically, C. eluta occurs only in northeastern Africa south to northern Tanzania, while C. nambiensis is known only from Namibia.

Types examined. Holotype and two paratypes: [ NAMIBIA]: Namibia, Erongo Distr., Farm Omandumba , 21°34’S 15°32’E. 10.–14.iii.2004, U. Göllner ( NMNW, MNHUB, MNHW);

Other specimens examined. NAMIBIA: n. Gobabis , Farm Ohlsenhagen , 22°19’S / 19°02’E, 10–12 III 2006, 1, U. Göllner ( ZMHU); Kraalkop farm, road Tsumeb to Groatfontein, 15 km SE of Tsumeb, 19°18’10.9’’S 17°47’16.8’’E, 1370 m, 5 II 2012, 1, R. Dobosz & G. Kopij ( USMB) .

Figures

FIGURE 27. Distribution of Cassida lycii (black diamond) and Cassida namibiensis (black squares).

FIGURES 204–206. Cassida namibensis.207–209. Cassida villiersi. 204–205, 207–208 Dorsal; 206, 209. Lateral.