Cassida voiensis, 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 : 176-177

Cassida voiensis sp. nov.

( figs. 47 , 196–198)

http://zoobank.org/ urn:lsid:zoobank.org:act:7E207142-C8FD-4EF5-A24E-F50360868525

Etymology. Named after its type locality, Voi in Kenya.

Description. L: 3.75–4.55 mm, W: 2.75–3.15 mm, Lp: 1.45–1.75 mm, Wp: 2.45–2.8 mm, L/W: 1.32–1.42, Wp/Lp: 1.60–1.72. Body oval, males distinctly stouter than female (figs. 196, 197).

Pronotum and scutellum yellow. Elytra yellow, in most specimens top of elytral disc with small reddish brown to brown spot and some punctures on sides of disc with brownish centre and areola thus form more or less complete U–shaped figure surrounding disc (fig. 197), often elytra uniformly yellow (fig. 196) or only spot on top of disc, sometimes punctures with brownish areola form also incomplete transverse band in 2/3 length of disc. Head yellow, often with ochraceous basal corners. Thorax from yellow to ochraceous, abdomen yellow, occasionally in centre slightly darker, ochraceous. Legs completely yellow, antennae usually yellow, sometimes one or two apical segments slightly infuscate.

Pronotum elliptical, with maximum width in the middle, sides rounded. Disc slightly convex, on sides separated from explanate margin by indistinct impression, without lateral lobes, area above head distinctly marked. Surface of disc shiny, with fine and sparse punctation, distance between punctures mostly wider than puncture diameter, sometimes surface appears impunctate. Explanate margin glabrous, smooth, shiny, transparent with well visible honeycomb structure.

Base of elytra moderately wider than base of pronotum, humeral angles moderately protruding anterad, sharply angulate. Disc moderately convex in profile (fig. 198), with shallow postscutellar and principal impressions, distinct H–shaped elevation, slightly convex second interval and few transverse elevations on sides of disc. Punctation coarse and dense, regular, punctures in rows almost touching each other.Marginal row distinct, with dense punctures, slightly smaller punctures in lateral rows. Intervals except elevated second interval very narrow, linear. Marginal interval well marked on entire length, broad, in anterior half almost as wide as submarginal interval and two submarginal rows combined, without humeral but with lateral folds. Surface of intervals shiny. Explanate margin moderately declivous, moderately broad, in the widest part five times narrower than disc. Surface of explanate margin very shallowly punctate, appears almost regular, glabrous, shiny, transparent with well marked honeycomb structure.

Eyes large, gena obsolete. Clypeus narrow, 1.1 times as long as wide. Clypeal grooves fine, runs close to margin of eye, at top converging in triangle. Surface of clypeal plate flat or with shallow impression apically, glabrous and shiny with several very small setose punctures. Part of clypeus between clypeal triangle and margin of eyes with a row of long hair. Labrum broadly emarginate to 1/4 length. Antennae stout, segments 9–10 slightly wider than long. Length ratio of antennal segments: 100:69:77:69:65:50:54:38:46:50:100. Segment 3 approximately 1.1 times as long as segment 2 and 1.1 times as long as segment 4.

Prosternal process broad, strongly expanded apically, area between coxa shallowly impressed, shiny, in the middle often with short groove, without special sculpture, with few small, setose punctures, rhomboidal apex flat, usually with longitudinal wrinkles and grooves and several small setose punctures, sometimes surface appears almost regular.

Claws with large basal tooth.

Distribution. Kenya ( fig. 47 ).

Remarks. A distinct species with no close relatives among African members of the genus Cassida . Its small size with length below 4.6 mm, elongate oval body, rounded pronotal sides, base of elytra only slightly wider than pronotum, elytral disc without hump only with H–shaped postscutellar elevation, regular elytral punctation and claws with a large basal tooth is a unique complex of characters. Maculate forms of C. eluta and C. namibiensisis are similar to maculate forms of C. voiensis but differ in the elytral pattern of numerous small brown to black spots spread over the entire surface of the disc ( figs. 193, 194 , 205 ) and prosternum at least partly brown to black while in C. voiensis the elytral pattern is restricted to small reddish to brown spots on the sides of the disc and a single spot on the postscutellar elevation, top of the disc is without spots (fig. 197) and prosternum is yellow. Immaculate forms of C. voiensis (fig. 196) are similar to immaculate forms of C. villiersi and C. namibiensis . The first species well differs in the punctate explanate margin of pronotum, the second species in a partly black thorax.

Types examined. Holotype: [ KENYA]: KENYA ( Tsavo ) / Voi 27.3–4.4.97 / Lgt. M. Snizek ( MNHW); four paratypes, the same data as holotype ( MNHW, MM); four paratypes: [ KENYA]: KENYA –S., / Voi / 23.XI.1997. / M. Snižek leg. ( MNHW, LS); two paratypes: [ KENYA]: KENYA / 22.XI–2.XII 1996 / Voi (Tsavo) / M. Snižek leg. ( MNHW); one paratype: [ KENYA]: KENYA SE / Kiboko env. / 21.XI.199 / M. Snižek leg. ( MNHW).

Figures

FIGURE 47. Distribution of Cassida tosta (black circles) and Cassida voiensis (black diamonds).

FIGURES 193–195. Cassida eluta. 196–198. Cassida voiensis. 193–194, 196–197. Dorsal; 195, 198. Lateral.

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