Cassida circumflexa Spaeth, 1926

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 : 45-46

Cassida circumflexa Spaeth, 1926

( figs. 39 , 168–169 )

Cassida circumflexa Spaeth, 1926 b: 88 ; Borowiec, 1999: 243; Rice, 2003: 80 .

Description. L: 4.90–5.30 mm, W: 4.40 mm, Lp: 1.70–1.80 mm, Wp: 3.15–3.40 mm, L/W: 1.11–1.20, Wp/Lp: 1–85–1.89. Body almost circular ( fig. 168 )

Pronotum yellow, disc with large black trapezoidal spot marked inside with two large yellow, oval spots. Scutellum black, elytral disc yellow with black pattern forming narrow band along suture, narrow bisinuate band along sides but with yellow marginal interval, and narrow transverse band across middle thus each elytron with two large yellow spots inside black figure ( fig. 168 ). Explanate margin always yellow. Head a yellow, prosternum and metasternum mostly brown to black except yellow lateral plates, abdomen yellow. Legs and antennae yellow, only apex of last segment infuscate.

Pronotum elliptical, with maximum width behind the middle, anterior margin regularly convex, sides subangulate, no basal corners. Disc indistinctly bordered from explanate margin, without lateral lobes, its surface shiny, with very fine pricks. Explanate margin broad, impunctate, shiny, transparent with well visible honeycomb structure.

Base of elytra slightly to moderately wider than base of pronotum, humeral angles moderately protruding anterad, angulate. Disc regularly convex in profile ( fig. 169 ), with very shallow postscutellar impressions, no principal impressions, without or with hardly marked H–shaped elevation. Punctation moderately coarse, arranged in completely regular rows, dense, distance between punctures from slightly narrower to as wide as puncture diameter. Postscutellar area and third interval with some additional irregular punctation. Marginal row distinct, its punctures not coarser than punctures in central rows. Intervals mostly as wide as to slightly wider than rows, flat, only intervals 2 and 4 twice wider than rows and slightly convex, marginal interval distinct, as wide as submarginal interval and row combined, no humeral or lateral folds. Explanate margin broad, moderately declivous, in the widest part three times narrower than disc, surface shiny, slightly irregular, transparent with well visible honeycomb structure.

Eyes very large, gena obsolete. Clypeus narrow, slightly longer than wide. Clypeal grooves fine but well marked, converging in regular arch, surface of clypeus flat, shiny, with several very small punctures. Labrum emarginate to 1/4 length. Antennae slim, segments 9–10 approximately twice as long as wide. Length ratio of antennal segments: 100:48:78:60:60:45:48:43:48:50:105. Segment 3 approximately 1.6 times as long as segment 2 and approximately 1.3 times as long as segment 4.

Prosternum broad in the middle, strongly expanded apically, area between coxa flat, without special sculpture, only with few small punctures, expanded apex with several moderately coarse shallow punctures and shallow rugosities.

Claws simple.

Distribution. Mozambique and Zimbabwe ( fig. 12 ).

Remarks. A very distinct species, its elytral pattern with narrow, black ring around disc combined with narrow black band across the middle and black suture of elytral disc are unique characters ( fig. 168 ). Only two other African members of the genus Cassida have an elytral pattern forming a black ring around the elytral disc— C. rabaiensis and C. wanati . Cassida rabaiensis differs in the elytral black ring broad, as wide as four lateral intervals combined and without a lateral emargination (figs. 174, 175) and in pronotal disc without a black basal spot, only with a diffused X–shaped mark (fig. 174) while in C. circumflexa the black ring occupies at most two lateral intervals combined and has broad emargination laterally ( fig. 169 ), and at the base of the pronotum has a large, trapezoidal, black mark with a pair of yellow spots inside. Cassida wanati differs in elytral pattern without transverse band and basal pronotal spot completely black, without yellow spots inside the black area (figs. 170, 171). Cassida circumflexa has no postscutellar H–shaped elevation while both relatives have such as low elevations.

Type examined. Holotype: [ MOZAMBIQUE]: Chibababa , Lower Buzi R., XII 1906, C.F.M. Swynnerton ( BMNH).

Other specimens examined. ZIMBABWE: Mazowe , Dam, 17°31’06”S, 30°59’13”E, 6 IX 1998, 1, M. Rice ( MER) .

Figures

FIGURE 12. Distribution of Cassida coagulata.

FIGURE 39. Distribution of Cassida rhodesiaca (black circles), Cassida rogozinskii (black sq uare) and Cassida circumflexa (black diamond).

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