Cassida natalensis Spaeth, 1932

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 : 113-115

Cassida natalensis Spaeth, 1932

( figs. 30 , 133–135 )

Cassida natalensis Spaeth, 1932: 238 ; Borowiec, 1999 a: 266.

Description. L: 4.05–5.20 mm, W: 3.20–4.00 mm, Lp: 1.45–1.80 mm, Wp: 2.50–3.10 mm, L/W: 1.20–1.33, Wp/ Lp: 1.72–1.87. Body short–oval, males slightly stouter than females ( figs. 133, 134 ).

In typically coloured specimens pronotum yellow with large black M–shaped figure of broadened base, sometimes also lateral lobes surrounded by black. In dark specimens pronotal disc mostly black with yellow V– shaped figure in front of scutellum. In pale specimens pronotal disc mostly yellow with brown to black V–shaped figure in front of scutellum, occasionally pronotum uniformly yellow. Scutellum yellow to partly infuscate. Elytral disc in typically coloured forms mostly black with numerous yellow, partly elevated spots arranged as in figs. 133 . In pale specimens top of disc predominantly yellow, sides predominantly black ( fig. 134 ). Head yellow to yellowish brown with black basal corners. Thorax black, abdomen from completely black to black centrally surrounded by yellow. Occasionally head and prosternum yellow and metasternum brown centrally and yellow laterally. In extreme case head, ventrites and legs uniformly yellow. Legs yellow except dark coxa. Antennal segments 1–9 yellow, last two apical segments gradually infuscate.

Pronotum elliptical, with maximum width in the middle, anterior margin regularly convex, sides broadly rounded, no basal corners. Disc more or less distinctly bordered from explanate margin with lateral lobes. Surface of disc from slightly alutaceous to shiny, from fine and sparse to moderately coarse and moderately dense punctation, specimens with largely black disc are finely punctate than specimens with largely yellow disc. Explanate margin broad, shiny, impunctate, transparent with well visible honeycomb structure.

Base of elytra from moderately to much wider than base of pronotum, humeral angles moderately protruding anterad, subangulate. Disc moderately convex in profile, with distinct postscutellar and principal impressions and distinct H–shaped figure ( fig. 135 ), in dark specimens the figure is often interrupted and divided into isolate yellow, elevated spots. Punctation coarse arranged in regular rows, but the regularity is often interrupted by elevated yellow sculpture. Punctation in rows dense, punctures almost touching each other. Marginal row distinct, its punctures not coarser than punctures in central rows. Intervals mostly linear, only second interval well marked, convex, sometimes also fourth interval in the middle more or less marked and convex, marginal interval as wide as or slightly narrower than submarginal one, humeral or lateral folds well marked. Explanate margin moderately broad, moderately declivous, in the widest part approximately four times narrower than disc, surface shiny with very shallow punctation, appears slightly irregular, transparent with well visible honeycomb structure.

Eyes very large, gena obsolete. Clypeus moderately broad, approximately as wide as long. Clypeal grooves fine but well marked, converging in regular triangle, surface of clypeus flat or with shallow apical impression, its surface strongly microreticulate with several very small, setose punctures. Labrum shallowly emarginate to 1/5 length. Antennae stout, segments 9–10 slightly transverse. Length ratio of antennal segments: 100:72:88:84:72:60:60:48:4 4:48:112. Segment 3 approximately 1.2 times as long as segment 2 and approximately as long as segment 4.

Prosternum moderately broad in the middle, strongly expanded apically, area between coxa impressed, with row of dense punctures along sides and some oblique wrinkles, expanded apex convex in the middle, impressed laterally, with several coarse, setose punctures.

Claws with small basal tooth, often appear untoothed.

Distribution. South Africa ( fig. 30 ).

Remarks. A member of the Cassida lacrymosa species–group. It belongs to the complex of species with a predominantly black surface of pronotal and elytral disc ( figs. 133, 134 ). The most similar species are the dark form of C. lacrymosa and the typical form of C. depicta . Cassida natalensis differs from both relatives in pronotal sides broadly rounded and pronotal black spot usually large, broadly M–shaped while in C. depicta and C. lacrymosa the pronotal sides are narrowly rounded and the pronotal spot usually small, V–shaped, only in the darkest forms M–shaped ( figs. 128, 129 , 185, 186 ). Cassida natalensis has a distribution area restricted to South Africa ( fig. 30 ) while both relatives are widely distributed in tropical Africa ( figs. 14 , 25 ). Similarly coloured C. irregularis differs in yellow ventrites and more rounded pronotal sides.

Types examined. Two syntypes: [ SOUTH AFRICA]: Natal, Weenen, II 1925 H.P. Thomasset ( BMNH, MM) .

Other specimens examined. SOUTH AFRICA: Mpumalanga, Berlin Plantation, -25.5722 / 30.7434, 1350 m, nr. Kaapsehoop, Barrets trail, wet forest, ravine, 4- 5.11.2013, 2, leg. R. Ruta, 2, leg. M. Wanata ( MNHW) ; Mpumalanga, Berlin Forest, -25.5722 / 30.7434, 1360 m, nr. Kaapsehoop, Barrets trail, rainforest, 4.11.2013, 1, leg. M. Wanata ( MNHW) ; E Transval, Berlin F. S., Sinkhole , 25.31 S / 30.46 E, 1, S. Endrödy – Younga ( MNHW) ; Transvaal, The Downs , 27 XI 1985, 1, Evans, Bellamy and Scholtz ( ER) ; Transvaal, Downs Forest , 30 km W Trichardtsdal, 1300 m, 23 XII 1985, 1, M. Sanborne ( MNHW) ; Transvaal , 30 km W Trichardtsdal, 30 XII 1985, 2, M. Sanborne ( MZSNV) ; Transvaal, Uitsoek, Grootklof ind. for., 25.15 S / 30.33 E, 25 X 1986, 6, S. Endrödy – Younga ( TM, MNHW) .

Figures

FIGURE 14. Distribution of Cassida depicta.

FIGURE 25. Distribution of Cassida lacrymosa.

FIGURE 30. Distribution of Cassida natalensis (black diamonds) and Cassida pudens (black circles). FIGURE 31. Distribution of Cassida wittmeri (black circles) and Cassida wanati (black diamond).

FIGURES 133–135. Cassida natalensis. 136–137. Cassida vespertilio. 133–134, 136. Dorsal; 135, 137. Lateral.

FIGURES 128–132. Cassida depicta. 128–129, 131–132. Dorsal; 130. Lateral.

FIGURES 182–187. Cassida lacrymosa. 182–183, 185–186. Dorsal; 184, 187. Lateral.