Cassida overlaeti, Borowiec & Świętojańska, 2022

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 : 118-120

Cassida overlaeti sp. nov.

( figs. 32 , 54–56)

http://zoobank.org/ urn:lsid:zoobank.org:act:0ADCD188-3926-4075-B15E-CDB66C1A12EE

Etymology. Named after G.F. Overlaet who collected holotype specimen.

Description. L: 7.30–8.75 mm, W: 6.00–6.45 mm, Lp: 2.55–2.90 mm, Wp: 4.50–5.20 mm, L/W: 1.23–1.36, Wp/Lp: 1.71–1.79. Body oval (figs. 54, 55).

Pronotum dark brown to black except yellow area above head and yellowish spot at base of explanate margin close to margin of disc. Scutellum and elytral disc from brown to black, elevated folds sometimes reddish brown, explanate margin uniformly brown to black with yellowish brown extreme lateral margin (figs. 54–56). Head, thorax and abdomen reddish brown, antennal segments 1–7 yellow, segments 8–11 infuscate to black.

Pronotum broadly elliptical, with maximum width in the middle, anterior margin regularly convex, sides very broadly rounded, no basal corners. Disc distinctly convex thus distinctly bordered from explanate margin but without lateral lobes with small shallowly impressed area above head, sides of disc bordered from explanate margin by distinct impression. Surface of disc shiny, impunctate, sides of disc often with shallow impression. Explanate margin broad, impunctate, only area above head semitransparent with well visible honeycomb structure.

Base of elytra much wider than base of pronotum, humeral angles moderately protruding anterad, subangulate, lateral margin of elytra behind the humeral angle often very shallowly emarginate. Disc very convex, with deep postscutellar and principal impressions, broad and moderately high H–shaped elevation and several folds behind the postscutellar elevation but without distinct hump (fig. 56), always are distinct short longitudinal folds on slope on second and third interval and oblique and transverse folds behind and laterally to H–shaped elevation, sides of disc behind humeri very shallowly impressed. Interspaces more or less elevated thus entire surface of disc appears more or less irregular. Punctation moderately coarse, tends to form regular rows, but they are interrupted and disturbed by elytral sculpture, only two submarginal rows mostly complete then distance between punctures smaller than puncture diameter. Marginal row distinct, its punctures usually coarser than punctures in central rows, interspaces mostly elevated. Intervals mostly disturbed by elytral relief only submarginal interval complete. Marginal interval distinct, in humeral area broad, as wide as submarginal interval and two submarginal rows combined, behind the middle usually as wide as or slightly narrower than submarginal interval, humeral and lateral folds distinct. Explanate margin moderately broad, moderately to strongly declivous, in the widest part five times narrower than disc, surface shiny, in pale form often almost impunctate and almost regular but usually with more or less distinct punctation, smaller in pale and coarser in dark forms then surface more or less irregular, only in pale forms semitransparent with more or less visible honeycomb structure.

Eyes large, gena slightly shorter than last palpomere. Clypeus very broad, approximately 1.7 times as wide as long. Clypeal grooves very fine but well marked, converging in triangle, clypeal plate strongly convex, its surface shiny with several very small, hairy punctures. Labrum minutely emarginate. Antennae moderately stout, segments 9–10 slightly longer than wide. Length ratio of antennal segments: 100:50:70:64:64:55:66:59:59:64:127. Segment 3 approximately 1.4 times as long as segment 2 and 1.1 times as long as segment 4.

Prosternum narrow in the middle, moderately expanded apically, area between coxa flat to slightly convex, shiny, without special sculpture but along sides and partly centrally with small, hairy punctures, expanded apex convex in the middle, slightly impressed laterally, surface shiny, on sides often with short impressed stripes or grooves, lateral alae along posterior margin with row of punctures, central part of expanded apex with small, hairy punctures.

Claws simple.

Distribution. Democratic Republic of Congo ( fig. 32 ).

Remarks. A member of the Cassida tosta species–group, has an intermediate position between C. inaequalis and C. tosta . Elytral sculpture is almost as strong as in C. tosta except the postscutellar elevation which is distinctly lower (fig. 56 vs. 59) and looks like the postscutellar elevation in C. inaequalis ( fig. 65 ). In C. overlaeti the sides of the elytral disc behind the humeri are shallowly impressed like in C. inaequalis while in C. tosta the impression is deep. Black forms of C. overlaeti distinctly differ from the typical form of C. tosta in completely brown to black explanate margin (fig. 54) while in C. tosta occurs reddish median spot ( fig. 57 ). Rare, dark forms of C. inaequalis always have the pronotum uniformly reddish to reddish brown ( fig. 66 ) while in the mostly brown form of C. overlaeti the pronotum is distinctly bicoloured with reddish anterior spots (fig. 55). Cassida altiuscula distinctly differs in a very high postscutellar elevation ( fig. 53 ) and elytral sides distinctly converging posterad ( figs. 51, 52 ).

Type examined. Holotype: [ DEMOCRATIC REPUBLIC OF CONGO (ZAIRE)]: Musée du Congo / Lulua: Kapanga / I–1933 / G. F. Overlaet // R. Dét. / E / 3219 ( MRAC); paratype: Musée du Congo / Kabambare / (Lt Delhaise) / Coll. Clavareau ( MNHW); paratype: I.R.S.A.C.– Mus. Congo / Kivu: Uvira, vallée de la / Mugadja 26–V–1958 / G. Marlier ( MRAC).

Figures

FIGURE 32. Distribution of Cassida overlaeti (black squares), Cassida viridipennis (black circles) and Cassida weinmanni (black diamonds).

FIGURES 63–66. Cassida inaequalis. FIGURES 67–68. Cassida blanda. 63–64, 66–67. Dorsal; 65, 68. Lateral.

FIGURES 57–62. Cassida tosta. 57–58, 60–62. Dorsal; 59. Lateral.

FIGURES 51–53. Cassida altiuscula. FIGURES 54–56. Cassida overlaeti. 51–52, 54–55. Dorsal; 53, 56. Lateral.