Cassida rabaiensis, 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 : 133

Cassida rabaiensis sp. nov.

( figs. 33 , 174–175)

http://zoobank.org/ urn:lsid:zoobank.org:act:B530BC3D-9B0C-4B77-A967-9ED6094E5C71

Etymology. Named after its type locality Rabai on coastal part of Kenya.

Description. L: 4.90 mm, W: 4.30 mm, Lp: 1.80 mm, Wp: 3.60 mm, L/W: 1.14, Wp/Lp: 2.00. Body regularly circular, without cleft between base of pronotum and base of elytra (fig. 174).

Pronotum yellow, disc with ochraceous X–shaped figure in front of scutellum marked with two small brown spots on ends of anterior branches, brown stripe in the middle and brown ends of basal branches. Scutellum brownish, elytral disc yellow with broad brown ring in the middle extending from fourth to eight rows of punctures, on base of disc the ring marked with two small yellowish patches, top of disc with two short brown stripes (fig. 174). Head ventrites and legs yellow, antennae yellow with two apical segments infuscate.

Pronotum semicircular, with maximum width at base, sides acute. Disc moderately convex, indistinctly bordered from explanate margin except lateral impression, area above head indistinctly impressed. Surface of disc shiny, with fine and sparse punctation. Distance between punctures distinctly wider than puncture diameter. Explanate margin broad, shiny, impunctate, semitransparent with more or less visible honeycomb structure.

Base of elytra as wide base of pronotum, humeral angles moderately protruding anterad, subangulate. Disc moderately convex in profile (fig. 175), with deep postscutellar and principal impressions, with well marked Hshaped elevation, interval 2 on entire length and interval 4 behind posterior branch of H–shaped elevation slightly convex. Punctation moderately coarse and dense, arranged in completely regular rows, punctures in rows almost touching each other. Marginal row distinct, its punctures as coarse as in central rows. Intervals at top of disc 1.5–2 times wider than rows, on sides of disc linear, marginal interval as wide as two submarginal rows and interval combined, humeral and lateral folds absent. Explanate margin moderately broad, moderately declivous, in the widest part four times narrower than disc, surface shiny, impunctate, semitransparent with more or less visible honeycomb structure.

Eyes very large, gena obsolete. Clypeus narrow, approximately as wide as long. Clypeal grooves fine, runs close to margin of eye, on top converging in angle, surface of clypeus flat, its surface shiny with few very small, setose punctures. Labrum narrowly emarginate to 1/6 length. Antennae moderately stout, segments 9–10 slightly longer than wide. Length ratio of antennal segments: 100:46:82:57:54:43:50:?:?:?:100. Segment 3 approximately 1.8 times as long as segment 2 and approximately 1.4 times as long as segment 4.

Prosternum moderately broad in the middle, strongly expanded apically, area between coxa flat, with short impressed median line, shiny, impunctate, expanded apex in the middle slightly convex, shiny with few small punctures, sides shallowly impressed, surface with fine longitudinal striation.

Claws simple.

Distribution. Kenya. Its type locality Rabai, also Rabai Mpya, is a historic location in Kilifi District in the Coast Province of Kenya about 12 miles northwest of the city of Mombasa ( fig. 33 ).

Remarks. A distinct species, elytral pattern with a broad, black ring around the disc and a regularly circular body shape without cleft between pronotum and elytra are unique characters (fig. 174). Only two other African members of the genus Cassida have an elytral pattern forming a black ring around the elytral disc— C. wanati and C. circumflexa . Both species differ in the base of elytra wider than pronotum and in the pronotal disc with a large, black basal spot ( figs. 168 , 170) while in C. rabaiensis the pronotal disc is mostly yellow with an X–shaped ochraceous figure marked with two small brown spots on the ends of the anterior branches, a brown stripe in the middle and brown ends of basal branches (fig. 174). Cassida wanati differs also in a narrow black elytral ring, not wider than the two lateral intervals combined and in the central yellow parts marked with a few black spots (figs. 170, 171). Cassida circumflexa differs also in the elytral pattern in addition to the black ring around disc also with a transverse band slightly behind the middle of the disc ( figs. 168, 169 ).

Type examined. Holotype: [ KENYA]: Kenya / van Someren / Rabai 8.37 ( MNHW).

Figures

FIGURE 33. Distribution of Cassida patruelis (black circles), Cassida pellegrini (black diamond) and Cassida rabaiensis (black square).

FIGURES 168–169. Cassida circumflexa. 170–171. Cassida wanati. 168, 170. Dorsal; 169, 171. Lateral.