Cassida villiersi, 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 : 172-173

Cassida villiersi sp. nov.

( figs. 44 , 207–209)

http://zoobank.org/ urn:lsid:zoobank.org:act:39911822-C8D4-409F-AA31-5B8FC77A37CB

Description. L: 4.10–4.85 mm, W: 3.15–3.65 mm, Lp: 1.55–1.80 mm, Wp: 2.55–3.05 mm, L/W: 1.27–1.37, Wp/ Lp: 1.65–1.71. Body short–oval (figs. 207, 208).

Dorsum uniformly ochraceous yellow to brownish, sometimes on top of postscutellar elevation small, brown spot (figs. 207, 208). Ventrites, including head, legs and antennae uniformly ochraceous yellow to brownish.

Pronotum elliptical, with maximum width behind the middle, anterior margin regularly convex, sides broadly rounded, no basal corners. Disc without lateral lobes, indistinctly bordered from explanate margin, area above head only slightly impressed, surface from slightly alutaceous to slightly shiny, with moderately coarse and dense punctation, distance between punctures from slightly to twice wider than puncture diameter, interspaces regular with distinct microreticulation, surface of disc appears from regular to slightly irregular. Explanate margin broad, with similar punctation as on disc, transparent with well visible honeycomb structure its surface from slightly alutaceous to shiny.

Base of elytra moderately wider than base of pronotum, humeral angles moderately protruding anterad, subangulate. Disc regularly convex in profile (fig. 209), with distinct postscutellar and principal impressions and high H–shaped postscutellar elevation. Punctation coarse and dense, arranged in completely regular rows, distance between punctures from slightly narrower to as wide as puncture diameter. Marginal row distinct, its punctures as coarse as in central rows. Intervals narrow, in sutural area as wide as rows, on sides slightly narrower than rows to linear, slightly convex especially second and fourth interval, interspaces often more or less convex, especially posterolaterally to H–shaped elevation form transverse folds. Marginal interval broad, as wide as submarginal interval and two rows combined, with distinct humeral and lateral folds. Explanate margin moderately broad, moderately declivous, in the widest part slightly more than four times narrower than disc, surface shiny, with moderately coarse and dense punctation, appears irregular, transparent with well visible honeycomb structure.

Eyes very large, gena obsolete. Clypeus broad, approximately 1.3 times as wide as long. Clypeal grooves fine but well marked, converging in regular triangle, surface of clypeus flat or with very small apical impression, shiny with few very small, setose punctures. Labrum broadly emarginate to 1/5 length. Antennae moderately slim, segments 9–10 slightly longer than wide. Length ratio of antennal segments: 100:52:76:66:62:48:52:38:41:48:100. Segment 3 approximately 1.5 times as long as segment 2 and approximately 1.2 times as long as segment 4.

Prosternum broad in the middle, strongly expanded apically, area between coxa flat, shiny, without special sculpture except small oblique grooves on sides, expanded apex flat with several moderately coarse, setose punctures.

Claws with large basal tooth.

Distribution. Burkina Faso and Niger ( fig. 44 ).

Remarks. A distinct species with no close relatives in African members of the genus Cassida . Its small size with length below 4.9 mm, ochraceous yellow dorsum without or with brown pattern, oval body, punctate pronotal disc, 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 large basal tooth is a unique complex of characters. Maculate forms of C. heroni and C. andreinii are similar to the maculate form of C. villiersi . The first species differs in its pale yellow dorsum, stouter body with L/W ratio 1.22–1.30 (in C. villiersi 1.27–1.37) and flat second interval (fig. 239), whereas the second species differs in its yellow to green dorsum, narrower and less explanate margin of elytra and flat second elytral interval ( figs. 236, 237 ) and in prosternum at least partly brown to black while in C. voiensis elytral pattern is restricted to small reddish to brown spots on sides of disc and a single spot on postscutellar elevation, top of disc without spots (fig. 197) and prosternum is yellow. Immaculate form of C. voiensis (fig. 196) is similar to immaculate forms of C. villiersi and C. namibiensis . First species well differs in punctate explanate margin of pronotum, the second species in partly black thorax.

Types examined. Holotype: [ NIGER]: Mt Baguezane , 1500–1600 m, 31 VIII–4 IX 1947, A. Villiers ( MNHW); 11 paratypes: the same data as holotype ( MNHW, LS); paratype: [ BURKINA FASO]: Haute Volta / Melou ( MNHW).

Figures

FIGURE 44. Distribution of Cassida stipidosa (black diamond), Cassida successiva (black circles) and Cassida villiersi (black squares).

FIGURES 236–238. Cassida andreinii. 239–240. Cassida heroni. 236–237, 239. Dorsal; 238, 240. Lateral.