Cassida oberlaenderi Spaeth, 1916

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 : 116-117

Cassida oberlaenderi Spaeth, 1916

( figs. 26 , 142–146 )

Cassida Oberländeri Spaeth, 1916: 49, 1925 a: 5 ; Borowiec, 1999 a: 269.

Cassida oberlanderi [sic]: Nummelin & Borowiec, 1991: 14.

Description. L: 5.80–7.00 mm, W: 5.05–5.90 mm, Lp: 2.00–2.35 mm, Wp: 3.55–4.20 mm, L/W: 1.12–1.20, Wp/ Lp: 1.73–1.88. Body almost circular, males slightly stouter than females ( figs. 142, 143. 145, 146 ).

In typically coloured specimens pronotum yellow, disc with black, goblet–shaped figure marked in the middle with yellow elongate spot or stripe and basal margin of sides of disc with transverse black spots. Scutellum yellow, elytral disc mostly black, on top with yellow irregular relief as in figs. 142–144 , marginal interval, broad lateral fold and extreme apex of disc yellow. Explanate margin always yellow. The pattern is quite constant and varies only in black to yellow ratio of space. In rare aberrations pronotum is uniformly yellow, elytral disc yellow without black pattern but punctures with brownish centre ( fig. 146 ), occasionally entire dorsum yellow ( fig. 145 ). Head, ventrites, legs and antennae yellow.

Pronotum broadly elliptical, with maximum width in the middle, anterior margin regularly, slightly convex, sides very broadly rounded, no basal corners. Disc bordered from explanate margin by narrow sulcus but without distinct lateral lobes. Surface of disc from shiny, impunctate, at most with very fine and sparse pricks. Explanate margin broad, impunctate, shiny, with well visible honeycomb structure.

Base of elytra much wider than base of pronotum, humeral angles distinctly protruding anterad, angulate, margin of elytra behind humeral angle usually shallowly emarginate. Disc very convex in profile, without hump ( fig. 144 ), with distinct postscutellar and principal impressions, and with obtuse H–shaped or X–shaped elevation, and yellow sculpture. Punctation moderately coarse, tends to form regular rows, but regularity is interrupted by impunctate yellow relief. Punctures in rows dense, interspaces narrower than puncture diameter. Marginal row distinct, its punctures only slightly coarser than punctures in central rows. Intervals marked only on slope and partly on sides of disc, on slope as wide as rows and slightly convex, on sides linear, marginal interval distinct, as wide as submarginal interval and submarginal row combined, without humeral but with large and broad lateral fold. Explanate margin broad, moderately declivous, in the widest part three times narrower than disc, surface shiny with very shallow and moderately dense punctation, appears only slightly irregular, transparent with well visible honeycomb structure.

Eyes large, gena very short but visible. Clypeus moderately broad, approximately as wide as long. Clypeal grooves fine but well marked, run close to margin of eye, on top converging in angle, surface of clypeus flat, shiny, with several very small setose, punctures. Labrum shallowly emarginate to 1/5 length. Antennae moderately stout, segments 9–10 slightly longer than wide. Length ratio of antennal segments: 100:50:65:60:55:45:50:50:50:55:100. 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 impressed to canaliculate, shiny, elevated sides with fain, short, oblique grooves, expanded apex slightly convex in the middle and shallowly impressed laterally with slightly irregular surface and several small setose punctures.

Claws with large basal tooth.

Distribution. Sierra Leone, Cameroon, Democratic Republic of Congo, Rwanda, Uganda, and Kenya ( fig. 26 ).

Remarks. A very distinct species. Its large size with length 5.80–7.00 mm, broadly rounded pronotal sides, elytral base distinctly wider than pronotum and body strongly convex, almost hemispherical, ( figs. 142–146 ) separates this species from all African members of the genus Cassida .

Types examined. Holotype: DEMOCRATIC REPUBLIC OF CONGO (ZAIRE): Beni ( NMW).

Other specimens examined. CAMEROON: Mueli , Nordseite Kamerungeb., 600 m, II 1958, 1, Hartwig ( MNHW); Sangmelima, IV 1933, 2, A.I. Good ( CMNH) .

DEMOCRATIC REPUBLIC OF CONGO (ZAIRE): Bambesa , I 1934, 1, H.J. Brédo ( MRAC) ; Ituri , 1, 1946, 1 ( LS) ; Bangala , Bunga, 8 III 1932, 1, H.J. Brédo ( MRAC) ; Lula , Kapanga, I 1933, 1, XI 1933, 1, F.G. Overlaet ( MRAC) ; Mongbwalu , Kilo, 1939, 1, Mme Scheitz ( MRAC) ; Port Francqui , IX 1937, 1, Mme Gillardin ( MRAC) ; Rutshuru , Pont Kako, 9 IX 1932, 1, L. Burgeon ( MRAC) .

KENYA: Kakamega Forest , 1800 m, 7–11 II 1999, 1, T. Wagner ( TW) ; Western Kakamega Forest NP., Buyangu– Isiukhu River , estuary Isiukhu R. – Busambuli R., 1500–1550 m, 22 XI 2002, 1, D. Bartsch & A. Zahm ( SMNS) ; Kakamega Forest N.P., Bujango, Udo’s camp, 1603 m, 17 I 2004, 1, F. Haas ( SMNS) .

RWANDA: Cyangugu Prov. , Nyakabuye, 1–30 XII 1982, 1, 1–15 V 1983, 1, H. Mühle ( HK, MD) .

SIERRA LEONE: Loma Mts. , closed canopy forest, 9°10’35”N, 11°05’25”W, 1050 m, 7–10 VI 2016, 1, Takano, Miles & Goff leg. ( BMNH) .

UGANDA: Budongo Forest Nat. P., 1.43 N / 31.32 E, 1224 m, 12–29 I 1997, 1, U. Göllner (MNHW); Budongo Forest, Sonso, 6–16 X 2004, 3, T. Wagner (TW); Kibale Forest, 18 IX 1984, 1, 16 XII 1984, 2, 17 I 1985, 1, 10 V 1985, 1, 12 IX 1986, 1, M. Nummelin (ZMUH, MNHW); Masindi Distr., Budongo Forest n. Sonso, 19–30 VI 1995, 2, 1–10 VII 1995, 1, 11–20 VII 1995, 2 ex. Trichilia rubescens (Meliaceae) , 21–30 VII 1995, 1 ex. Rinorea ardisiifolia (Violaceae) , 15–25 I 1997, 1, T. Wagner (TW, MNHW); Toro Distr., Ft. Portal, Kibale Forest, V–IX 1992, 2 (JM).

Figures

FIGURE 26. Distribution of Cassida litigiosa (black circles), Cassida nigeriana (black square) and Cassida oberlaenderi (black diamonds).

FIGURES 142–146. Cassida oberlaenderi. 142–143, 145–146. Dorsal; 144. Lateral.