Cassida mashonensis Spaeth, 1928

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 : 107-109

Cassida mashonensis Spaeth, 1928

( figs. 28 , 279–281)

Cassida mashonensis Spaeth, 1928: 10 ; Borowiec, 1999 a: 264.

Description. L: 5.15–5.55 mm, W: 3.90–4.35 mm, Lp: 1.90–2.05 mm, Wp: 3.30–3.40 mm, L/W: 1.28–1.32, Wp/ Lp: 1.65–1.74. Body oval to elongate–oval, regularly rounded on sides (figs. 279, 280).

Pronotum and scutellum yellow. Elytral disc yellow or yellowish green, usually with reddish or reddish brown pattern forming a lyriform figure, area between the figure and margin of disc yellow, central part of disc more or less yellow but some punctures often with reddish to reddish brown centre (fig. 280). In the palest specimens the pattern is reduced to small spots on humeri and in posterolateral parts of disc, darker punctures in scutellar row, apical part of sutural row and behind the middle of second interval (fig. 279). Head, ventrites, legs and antennae yellow, last segment sometimes with slightly infuscate apex.

Pronotum elliptical, with maximum width in the middle, anterior margin regularly convex, sides broadly rounded, no basal corners. Disc indistinctly bordered from explanate margin, without lateral lobes. Surface of disc from slightly alutaceous to shiny, usually with moderately coarse and moderately dense punctation, distance between punctures from slightly narrower to twice wider than puncture diameter, but surface appears more or less regular, but some specimens have very small and sparse punctation. Explanate margin broad, impunctate, shiny, its surface smooth to only slightly irregular, transparent with well visible honeycomb structure.

Base of elytra moderately wider than base of pronotum, humeral angles moderately protruding anterad, subangulate. Disc almost regularly convex in profile (fig. 281), with distinct postscutellar and principal impressions and H–shaped elevation. Punctation coarse arranged mostly in completely regular rows, only in postscutellar impressions irregular, and laterally to H–shaped elevation with additional irregular punctures, Punctures in rows dense, almost touching each other. Marginal row distinct, its punctures only slightly coarser than punctures in central rows. Intervals mostly linear, only second interval as wide as rows and slightly convex, and two submarginal intervals also as wide as rows but flat, no humeral or lateral folds but interspaces of marginal row usually more or less convex. Explanate margin narrow, strongly declivous, in the widest part five times narrower than disc, surface shiny, with shallow but coarse and dense punctation and irregular interspaces, appears rugose, transparent with well visible honeycomb structure.

Eyes very large, gena obsolete. Clypeus broad, approximately 1.2 times as wide as long. Clypeal grooves fine but well marked, converging in triangle with obtuse top, surface of clypeus flat or very shallowly impressed, its surface shiny with few very small, setose punctures. Labrum broadly emarginate to 1/6 length.Antennae moderately stout, segments 9–10 approximately as long as wide. Length ratio of antennal segments: 100:56:74:68:65:47:59:56: 62:68:108. Segment 3 approximately 1.3 times as long as segment 2 and approximately 1.1 times as long as segment 4.

Prosternum moderately broad in the middle, strongly expanded apically, area between coxa flat to shallowly impressed, without special sculpture except few very small, setose punctures, expanded apex slightly convex, central part shiny, along posterior margin two rows of moderately coarse, setose punctures.

Claws with large basal tooth.

Distribution. Kenya, Zimbabwe, and Namibia ( fig. 28 ).

Remarks. A member of the Cassida viridipennis species–group. It belongs to the complex of species with broad elytra and, elytral punctation partly regular. The complex comprises also C. granula and C. viridipennis . Cassida granula differs in the yellow background of the elytra and the central part of elytral disc partly red due to the reddish centres of punctures and red lateral stripes (figs. 250, 251) while in C. mashonensis the yellow background occupies only the central part of the disc while the sides and apex are green or yellowish green and the pattern is reddish brown or brown spread mostly on the sides of the central yellow spot (figs. 279, 280). Both species are separated geographically, C. granula is widespread in West and Central Africa ( fig. 18 ) while C. mashonensis is known from eastern and southern Africa ( fig. 28 ). Typical forms of C. viridipennis distinctly differ in dorsum uniformly green or yellowish green ( figs. 246, 247 ). Maculate forms of C. viridipennis differ in pronotal disc impunctate or at most finely punctate with distance between punctures always wider than puncture diameter and in body less regularly oval with sides slightly converging posterad ( fig. 249 ).

Types examined. Two syntypes: [ ZIMBABWE]: Mashonaland, Salisbury, G.A. Marshall ( BMNH, MM) .

Other specimens examined. KENYA: Rabai , VIII 1937, 2, Van Someren ( BMNH, MNHW) .

MALAWI: Chikawa , Lower Shire Valley, 16 IV 1920, 1 ( LS) .

NAMIBIA: Abachaus , II 1953, 1, G. Hoboh ( MNHW) .

Figures

FIGURE 18. Distribution of Cassida granula (black circles) and Cassida limpopoana (black diamonds).

FIGURE 28. Distribution of Cassida mashonensis (black diamonds), Cassida minutissima (black square) and Cassida pernix (black circles).

FIGURES 246–249. Cassida viridipennis. 250–251. Cassida granula. 246–247, 249–250. Dorsal; 248, 251. Lateral.