Cassida tosta Klug, 1835

(figs. 47, 57–62)

Cassida tosta Klug, 1835: 47; Boheman, 1854: 486, 1856: 146, 1862: 350; Thomson, 1858: 230; Gemminger & Harold, 1876: 3659; Karsch, 1882: 401; Spaeth, 1902: 459, 1903: 178, 1916: 41, 1925 a: 5; Shaw, 1961: 32, 1963: 460, 1968 a: 371, 1968 b: 782; Borowiec, 1985: 240, 1986: 805, 1999 a: 288; Nummelin & Borowiec, 1991: 14.

Cassida (Cassida) tosta: Spaeth, 1914 b: 118.

Cassida fossulata Boheman, 1856: 142, 1862: 350 (as syn. of tosta); Gemminger & Harold, 1876: 3654.

Cassida rugipennis Spaeth, 1902: 456; Shaw, 1968 a: 371 (not Cassida rugipennis Boheman, 1855); Borowiec, 1999 a: 288 (as syn. of tosta).

Cassida (Cassida) rugipennis: Spaeth, 1914 b: 118.

Description. L: 6.60–8.30 mm, W: 5.15–6.50 mm, Lp: 2.35–2.85 mm, Wp: 4.15–5.10 mm, L/W: 1.24–1.36, Wp/ Lp: 1.73–1.92. Body oval, on sides slightly rounded (figs. 57, 58, 60–62).

Very variable species. In typically coloured specimens pronotum brown to black, only area above head yellow to reddish, scutellum from yellowish to brown, elytral disc brown to black, explanate margin of elytra mostly brown to black with broad, yellow fenestrate spot in 1/3 length and yellow extreme lateral margin of elytra (figs. 57, 58); head, ventrites, legs and antennae yellow to ochraceous. In dark specimens entire elytra black and four apical antennal segments infuscate to black (fig. 62). In pale specimens pronotum ochraceous, elytral disc reddish brown and explanate margin of elytra brown with broad, yellow fenestrate spot and yellow extreme margin (fig. 61). In mostly brown specimens often sides of disc darker than top of disc. In extreme pale forms dorsum uniformly yellowish red or ochraceous (fig. 60). In pale forms antennae always uniformly yellow.

Pronotum regularly elliptical, with maximum width in the middle, anterior margin regularly convex, sides very broadly rounded, no basal corners. Disc distinctly bordered from explanate margin but without lateral lobes, with distinct lateral impressions. Surface of disc shiny, impunctate, base in front of scutellum with two impressions. Explanate margin broad, shiny, impunctate, without radial impressions, only pale area above head transparent with well visible honeycomb structure.

Base of elytra much wider than base of pronotum, humeral angles strongly protruding anterad, subangulate to angulate. Disc strongly convex with low and obtuse postscutellar hump (fig. 59), entire surface with longitudinal and transverse folds, the highest on slope, elytral disc behind humeri distinctly impressed. Punctation moderately coarse, tends to form regular rows but the regularity interrupted by elevated elytral sculpture, only between humeral callus and folds on slope runs regular one or two rows, interspaces shiny. Marginal row distinct, its punctures twice coarser than punctation in central and lateral parts of disc. Intervals mostly indistinctly marked except almost complete submarginal one, marginal interval slightly narrower than submarginal one interrupted by few high folds. Explanate margin narrow, moderately declivous, in the widest part five times narrower than disc, surface irregular with mixed wrinkles and punctation but shiny interspaces, not transparent, honeycomb structure visible only on fenestrate spot or in completely pale specimens.

Eyes large, gena as long as last palpomere. Clypeus very broad, approximately 1.6 times as wide as long. Clypeal grooves fine but well marked, converging in arch, clypeal plate strongly convex, shiny, with few small setose punctures. Labrum without median emargination, only anterior margin very broadly and shallowly emarginate. Antennae moderately slim, segments 9–10 slightly longer than wide. Length ratio of antennal segments: 100:50:74:71:67:60:67:57:60:62:110. Segment 3 approximately 1.5 times as long as segment 2 and approximately as long as segment 4.

Prosternum moderately broad in the middle, strongly expanded apically, between coxae flat, without special structure but sparsely pubescent, expanded apex in the middle strongly convex, on sides deeply impressed with several long setae.

Claws simple but with distinctly widened base.

Distribution. Forest regions of West and Central Africa (fig. 47).

Remarks. Cassida tosta is a member of the Cassida tosta species–group and with C. altiuscula and C. overlaeti forms aberrations with mostly black elytra. Cassida altiuscula distinctly differs in a very high postscutellar elevation (fig. 53) and elytral sides distinctly converging posterad (figs. 51, 52). Cassida overlaeti differs in a very low postscutellar elevation (fig. 56 vs 59) and elytral disc behind humeral callus shallowly impressed (fig. 54). Pale forms of C. tosta (fig. 60) are similar to C. inaequalis but differ in a higher postscutellar elevation (fig. 59 vs. 65), elytral disc behind humeral callus distinctly impressed and sculpture on slope of elytral disc higher (fig. 69 vs. 63).

Types examined. Holotype of Cassida tosta Klug, 1835: [PRINCIPE IS.]: Isle de Prince, Klug (ZMHU); lectotype and paralectotype of Cassida fossulata Boheman, 1856: [NIGARIA]: Old Calabar (NRS); two syntypes of Cassida rugipennis Spaeth, 1902: [ANGOLA KABINDA]: Chiloango, M. Tschoffen (MM).

Other specimens examined. BENIN: Dahomey, 1, Ponillon (MRAC); Kisou, 1 (ZMHU); Porto Novo, Daltonoay, 1 (NMP); Zagnanano, 1 (ZMHU).

BURKINA FASO: Haute Volta, Melou, 1 (IRSN).

CAMEROON: Barombi St., 1, Zeuner (ZMHU), Conradt, 2 (MNHW); Batanga, V 1914, 1, F.H. Hope (MNHW); Bipindi, IV 1897, 3, VIII–IX 1898, 4, G. Zenker (ZMHU); Buea, 1000 m, 2–7 III 1912, 1, Rothkirch (ZMHU); Jaunde, X 1914, 2, Tesmann (ZMHU); Joh.–Albrechthöhe, 2, 11 IV–27 V 1898, 1, L. Conradt (ZMHU); Joko, 6 (ZMHU), III 1912, 1, Moser (MRAC); Kamerunberg, Soppo, 730 m, 1912, 1, Rothkirch (MNHW); Katho– Barombi See, I 1958, 1, Hartwig (MNHW); Lolodorf, VI 1914, 1, J.A. Reis (CMNH), VI 1925, A.I. Good (CMNH); Malende–Banga, 125 m, 5–20 XII 1957, 1, H. Knorr (SMNS); Min Kama, 5 VI 1974, 1, B. de Miré (HPA); Moliwe n. Victoria, 18–30 XI 1902, 1, 1–17 I 1908, 1, F. v. Maltzan (ZMHU); Njam–Njam, Semnio, 1, Bohndorff (ZMHU); N’Ten, 1907, 1, Cottes (MNHN); Nyassosso, 25–27 II 1898, 1, L. Conradt (ZMHU); Soppo, II 1912, 2, Rothkirch (ZMHU); Tibati, 1 (ZMHU); Tome n. Victoria, 22–31 I 1980, 6, Polish Students Exp. (MNHW); Yaunde St., 1, v. Carnap (ZMHU); Wamba, 1 (ZMHU).

DEMOCRATIC REPUBLIC OF CONGO (ZAIRE): Albert Nat. Park, Mont Hoyo, grotte Yolohafiri, 10130 m, 8–9 VIII 1955, 1, P. Vanschuytbroeck (MRAC); Albert Nat. Park, Ruwenzori, Mutawanga, 1000–1300 m, XI 1936 – II 1937, 1, Hackars (MRAC); Albert Nat. Park, Secteur Nord, Kitulu, marais près riv. Rugetsi, 1150 m, 5 X 1956, 1, P. Vanschuytbroeck (MRAC); Albertville, XII 1918, 1, R. Mayné (MRAC); Bamania, 1934, 1, F. Longinus (MRAC); Bambesa, 20 VIII 1933, 1, J. Leroy (MRAC), IV 1939, 1, J. Vrydagh (MRAC); Barumbu, VII 1925, 1, J. Ghesquière (MRAC); Bas Ubili, 1, L. Burgeon (MRAC); Bokalala, Bolobo, 1954, 2, R.C. Eloy (MRAC, MNHW); Congo da Lemba, X–XII 1911, 1, R. Mayné (MRAC); Dima, 26 IX 1908, 1, A. Koller (MRAC); Eala–Bokatola–Bikoro, IX–X 1930, 1, P. Staner (MRAC); Elisabethville, 1935, 2, Richard (MRAC); Equateur, Bokuma, I–II 1952, 1, VII 1952, 7, Lootens (MRAC, MNHW); Equateur, Flandria, IX 1935, 1, J. Ghesquière (MRAC); Haut Uele, Moto, 1923, 1, L. Burgeon (MRAC); Haut Uele, Watsa, 1, L. Burgeon (MRAC); Ibembe, Haut Itimbiri, V 1810, J. Duvivier (IRSN); Kasai, Kondue, 5, E. Luja (MRAC); Kasongo, VIII–IX 1959, 1, P.L.G. Benoit (MNHW); Katanga, Kamina, II–III 1960, 1, A. Froidebise (MRAC); Kikwit, 1920, 1, P. Vanderijst (MRAC); Kindu, XI 1913, 1, L. Burgeon (MRAC); Kivu, Kanambo, Vall. de la Ruzizi, III 1959, 6, P.L.G. Benoit (MRAC, MNHW); Kiwele, Kwango, 18 VIII 1968, 1, P.M. Elsen (MRAC); Kunungu, 1930, 1, Nkele (MRAC); Kwango–Ngowa, 25 XI 1937, 3, J. Martens (IRSN, MNHW); Lisala Reg., 11 VII 1938, 1, J. Deheyn (MRAC); Lulua, Kapanga, XII 1931, 1, II 1932, 1, II 1933, 1, G. Overlaet (MRAC); Maniema, Kasongo, VIII–IX 1959, 3, P.L.G. Benoit (2 MRAC, 1 MNHW); Maniema, Kindu, 1917, 1, L. Burgeon (MNHN); Maniema, Maleba, VIII 1932, 1, L. Lebrun (MRAC); Maniema, Maleka, VIII 1932, 1, L. Lebrun (MRAC); Mayidi, 1945, 1, P. Van Eyen (MRAC); Mayumbe, Zobe, 4–12 I 1916, 1, R. Mayné (MRAC); Ngowa, X–XI 1938, 2, 2 XI 1939, 1, J. Mertens (IRSN, MNHW); Région des Lacs, 1, Sagona (MRAC); Stanleyfalls, 1, R.P. Kohl (NNML); Tshenge–Kwimba, 4 X 1924, 1, A. Collart (IRSN); Tshuapa, Bamanya, I 1963, 1, VII 1965, 1, Hulstaert (MRAC); Tshuapa, Etata, VII–IX 1970, 1, J. Hauwaerts (MRAC); Tshuapa, Lukolela, 1, De Guide (MRAC); Ubangi, Bomboma, VIII 1935, 1, A. Bal (MRAC); Ubangi, Nzali, 3–4 II 1932, 8, H.J. Brédo (MRAC); Uele, 1 (HNHM); Uele, Dingila, 22 II 1933, 1, J. Vrydagh (MRAC); Uele, Ibembo, IX 1951, 1, F. Hutsebaut (MRAC); Yangambi, 24 V 1933, 1, J. Vrydagh (MRAC), X 1956, 1, N. L. H. Krauss (BMNH); Yangambi, Stanleyville, V 1959, 3, P. Dessart (MRAC, MNHW).

EQUATORIAL GUINEA: Benitogeb., Alén, 1–15 IX 1906, 1, G. Tesmann (ZMHU); Fernando Poo, Santa Isabel, VII–VIII 1900, 1, L. Conradt (ZMHU); Mongo, 1946–1948, 1, J. Palau (MRAC), 9 VII 1947, 1, J. Palau (MCNB); Nkolentangan, XI 1907 – V 1908, 4, G. Tesmann (ZMHU).

ETHIOPIA: Illubabor prov., 30 km W Abobo, 22–30 VIII 1988, 1, L. Medvedev (LM).

GABON: between Lambarene et sea coast, 1901, 1, E. Haug (MNHN); Ogove R., 4, Good (CMNH); Sud Ogowé, 1, Junod (MRAC).

GHANA: Ashante, 2, Simon (ZMHU).

IVORY COAST: Andé, Bongouanou, II 1962, 1, J. Decelle (MRAC); Assinie, 1 (ZMHU), 1 (MRAC); Bingerville, I 1964, 2, II 1964, 1, III 1964, 2, J.Decelle (MRAC, MNHW); Dimbroko, 1 (MNHW); Haut Cavally, Danane, 1909, 1, S. Bonnaure (MNHN); Haute Nugo and Haute Cavally, n. Danane, 1910, 1, A. Chevalier (MNHN); Irho La Me, 13–16 IX 1979, 1, J.M. Maldes (HPA); Monyassué, Aboisso, XI 1962, 1, J. Decelle (MRAC); San Pedro, 2, 1901, G. Thoire (MNHN).

LIBERIA: border of Liberia, Guinea and Ivory Coast, 1910, 1, Roeckel (MNHN).

NIGERIA: Kabba Prov., Lokoja, 24–28 II 1949, 1, B. Malkin (CAS); Lagos, VIII–IX 1948, 6, W. E. S. Merett (BMNH, LS); Old Calabar, 1 (IRSN), 2 (ZMHU).

REPUBLIC OF CENTRAL AFRICA: Fort Sibut, Oubanchi–Chari, 2 (LS, NMP).

SIERRA LEONE: Loma Mts., farmland/mosaic forest 9°07’47”N, 11°05’24”W, 420 m, 11–15 VI 2016, 1, Takano, Miles & Goff leg. (BMNH).

TANZANIA: Victoria Lake, Ukerewe Is., 1, Conradts (ZMHU).

TOGO: Bena, 12 IX 1973, 1, R. Linnavuori (ZMUH); Bismarckburg, 1, 1 V–23 VI 1893, 1, 27 VI–8 VII 1893, 1, L. Conradts (ZMHU).

UGANDA: Buamba Forest, Semliki Valley, 2.300 –2.800 ft., 3–7 XI 1911, 1, S. A. Neave (BMNH); Durro Forest, Toro, 4.400 –4.500 ft., 25–29 X 1911, 1, S. A. Neave (BMNH); Entebbe, 1, C. A. Wiggins (BMNH), 5–11 VII 1911, 9, 1–11 IX 1911, 2, S. A. Neave (BMNH, LS), 17 VIII 1911, 1, 10–14 II 1914, 2, C.C. Gowdey (BMNH); 4 mls of Entebbe, Kitabi Hill, 3800–4000 ft., X 1913, 1, C.A. Wiggins (HOC); 3–4 mls NE of Entebbe, Sebogwawo, 25 VI 1912, 1, C.A. Wiggins (HOC); Kibale Forest, 17 I 1985, 1, 6 V 1985, 1, 13 V 1985, 1, 19 IX 1986, 2, M. Nummelin (ZMUH, MNHW); Mabira Forest, 1 VII 1913, 1, C. C. Godwey (BMNH), 6 X 2004, 1, T. Wagner (TW); Mabira Forest, Chagwe, 3.500 –3.800 ft., 16–25 VII 1911, 1, S. A. Neave (BMNH).