Cassida inaequalis Thomson, 1858

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 : 86-88

Cassida inaequalis Thomson, 1858

( figs. 21 , 63–66 )

Cassida inaequalis Thomson, 1858: 231 ; Boheman, 1862: 362; Gemminger & Harold, 1876: 3654; Spaeth, 1902: 458; 1903: 178, 1916: 41; Borowiec, 1985: 240, 1999: 257; Nummelin & Borowiec, 1991: 14.

Cassida (Cassida) inaequalis: Spaeth, 1914 b: 117 .

Cassida marginata var. inaequalis: Spaeth, 1903: 178 .

Cassida marginata Weise, 1898: 220 ; Spaeth, 1902: 458, 1903: 178, new synonymy.

Cassida (Cassida) inaequalis var. marginata: Spaeth, 1914 b: 117 .

Description. L: 7.05–8.50 mm, W: 5.55–6.60 mm, Lp: 2.50–2.80 mm, Wp: 4.30–5.05 mm, L/W: 1.21–1.36, Wp/ Lp: 1.65–1.90. Body oval ( fig. 46 ).

Variable species. In typically coloured specimens dorsum reddish–brown, head, thorax and abdomen yellowish to ochraceous, antennal segments 1–7 yellow, segments 8–11 infuscate to black ( figs. 63, 64 ). In some specimens thorax more or less brown to almost black, abdomen dark brown centrally surrounded by ochraceous to pale brown, legs mostly brown to almost black with paler apex of femora. In quite common aberration pronotum, elytral disc and ventrites as in typical form but explanate margin of elytra black except pale extreme margin (= ab. marginata Weise , fig. 66 ), often the form with black explanate margin has black thorax and legs but abdomen pale or only slightly infuscate centrally. In all forms pronotum always unicolour, from reddish brown to brown, without pale „windows” on explanate margin and antennae always with infuscate to black distal segments. Occasionally, entire dorsum dark brown to black.

Pronotum broadly elliptical, with maximum width in the middle, anterior margin regularly convex, sides very broadly rounded, no basal corners. Disc distinctly convex thus distinctly bordered from explanate margin but without lateral lobes with small shallowly impressed area above head, sides of disc bordered from explanate margin by distinct impression. Surface of disc shiny, impunctate, sides of disc often with shallow impression. Explanate margin broad, impunctate, shiny, only in pale forms semitransparent with well visible honeycomb structure.

Base of elytra much wider than base of pronotum, humeral angles moderately protruding anterad, subangulate, lateral margin of elytra behind the humeral angle often very shallowly emarginate. Disc very convex, with deep postscutellar and principal impressions, postscutellar hump very low and obtuse but distinctly marked with broad and low H–shaped elevation and several folds behind the postscutellar elevation, always are distinct short longitudinal folds on slope on second and third interval and oblique and transverse folds behind and laterally to H–shaped elevation, sides of disc behind humeri not impressed. Interspaces more or less elevated thus entire surface of disc appears more or less irregular. Punctation moderately coarse, tends to form regular rows, but they are interrupted and disturbed by elytral sculpture, only two submarginal rows mostly complete then distance between punctures smaller than puncture diameter. Marginal row distinct, its punctures usually coarser than punctures in central rows, interspaces mostly elevated. Intervals mostly disturbed by elytral relief only submarginal interval complete. Marginal interval distinct, in humeral area broad, as wide as submarginal interval and two submarginal rows combined, behind the middle usually as wide as or slightly narrower than submarginal interval, humeral and lateral folds distinct. Explanate margin moderately broad, moderately to strongly declivous, in the widest part five times narrower than disc, surface shiny, in pale form often almost impunctate and almost regular but usually with more or less distinct punctation, smaller in pale and coarser in dark forms then surface more or less irregular, only in pale forms semitransparent with more or less visible honeycomb structure.

Eyes very large, gena as long as last palpomere. Clypeus very broad, approximately 1.8 times as wide as long. Clypeal grooves very fine but well marked, converging in triangle, clypeal plate strongly convex, its surface shiny with several very small, hairy punctures. Labrum minutely emarginate. Antennae moderately stout, segments 9–10 slightly longer than wide. Length ratio of antennal segments: 100:50:70:73:64:57:59:57:57:59:114. Segment 3 approximately 1.4 times as long as segment 2 and slightly shorter than segment 4.

Prosternum narrow in the middle, moderately expanded apically, area between coxa flat to slightly convex, shiny, without special sculpture but along sides and partly centrally with small, hairy punctures, expanded apex with globular elevation in the middle, slightly impressed laterally, surface shiny, on sides often with short impressed stripes or grooves, lateral alae along posterior margin with row of punctures, central part of expanded apex with small, hairy punctures.

Claws simple.

Distribution. Western and Central Africa from Guinea to Uganda ( fig. 22 ).

Remarks. A member of the Cassida tosta species–group, the only species of the group which never forms mostly black aberrations, at most the explanate margin of elytra can be completely black ( fig. 66 ). Cassida altiuscula differs in completely black elytra, very high elytral hump ( fig. 53 ), elytral sides distinctly converging posterad, and base of elytra is the most widest in relatio to base of pronotum within the group ( figs. 51, 52 ). Brown forms of C. overlaeti are similar to dark forms of C. inaequalis but differ in pronotum mostly brown with reddish anterior spots while in all forms of C. inaequalis the pronotum is uniformly reddish to reddish brown ( figs. 63. 64, 66 ). 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 ( figs. 69 vs. 63).

Types examined. Type location of Cassida inaequalis Thomson, 1858 unknown; lectotype and paralectotype of Cassida marginata Weise, 1898 (designated by Borowiec, 1999: 257): [ CAMEROON]: Kamerun, Kraatz (ZMHU).

Other specimens examined. ANGOLA: Kwanza Norte Prov., near N’Dalatando , 22 XI 2013, 1, T. Lackner leg. ( BMNH) .

CAMEROON: Barombi St. , 1, Zeuner ( ZMHU) ; Batanga , III 1914, 2, IV 1914, 5, F.H. Hope ( CMNH) ; Bipindi , 1898, 1, G. Zenker ( ZMHU) ; Camerun , 1, Sjoestedt ( NRS) ; Dengdeng , Godje, 20 III 1914, Hildbreaed ( ZMHU) ; Edea , 6 VI 1922, 1, J.A. Reis ( CMNH) ; Efulen , XI 1912, 3, J.A. Reis ( CMNH) ; Jaunde , IV–V 1897, 1, v. Carnap ( ZMHU) ; Joh.–Albrechthöhe , 28 V–12 VI 1898, 2, 11 VII–2 VIII 1898, 2, 3–28 VIII 1898, 1, L. Conradt ( ZMHU) ; Joko , 1 ( HNHM) ; Katho–Barombi See , I 1958, 5, W. Hartwig ( MKB) ; Kribi , 1 ( MRAC) ; Lolodorf , 19 II–7 VI 1895, 5, L. Conradt ( ZMHU) ; 15 III 1919, 1, J.A. Reis ( CMNH) , III 1925, 1, A.I. Good ( CMNH) ; Mt. Kamerun , 600 m, II 1958, 1, Hartwig ( MKB) ; 5 km S Muëli , 6 II 1958, 1, H. Knorr ( SMNS) ; Mundame , 2 ( IRSN) , 1, R. Rohde ( ZMHU) ; Nkolbisson , Dept. Nyong–Sanaga, X 1963, 1, L.G. Segers ( MRAC) ; Yaunde St. , 1, v. Carnap ( ZMHU) .

DEMOCRATIC REPUBLIC OF CONGO (ZAIRE): Albert Nat. Park , Massif Ruwenzori , riv. Lume (moyenne), affl. Semliki, 1830 m, 30 VIII 1956, 1, P. Vanschuytbroeck ( MRAC) ; Albert Nat. Park , Mutsora , 1939, 4, Hackars (3 MRAC, 1 MNHW); Albert Nat. Park , Secteur Nord , riv. May ya moto, affl. g. Talya, 1280 m, 3 IX 1957, 1, P. Vanschuytbroeck ( MRAC) ; Albert Nat. Park , Secteur Nord , Molidi, affl. dr. Byangolo, 1140 m, 29 I 1957, 1, P. Vanschuytbroeck ( MRAC) ; Albert Nat. Park , r. Tungula , piste Mwenda, Kafuka, 1000 m, 27 III 1947, 1, J. de Wilde ( MRAC) ; Bambesa , III 1937, 1, 24 IV 1937, 1, J. Vrydagh ( MRAC) ; Beni, 1, Lt. Bonnevie ( MRAC) ; Bas Uele, Buta, 1926, 1, F. Joseph ( MRAC) ; Bas Uele , Djamba, 17–25 XII 1924, 1, H. Schouteden ( MRAC) ; Bas Uele , Koteli, 1–21 I 1925, 1, H. Schouteden ( MRAC) ; Bokoro , 20 III 1915, 1, R. Mayné ( MRAC) ; Bomboma , 20 VII 1935, 1, A. Bal ( MRAC) ; Djombo , 25 X 1912, 1, R. Mayné ( MRAC) ; Elisabethville, 1935, 1, Richard ( MRAC) ; Equateur, Bokote, 1922, 1, Hulstaert ( MRAC) ; Kasai, Kondue, 6, E. Luja ( MRAC) ; Kindu , XI 1913, 1, L. Burgeon ( MRAC) ; Kivu , vall. de la Ruzizi, Kanambo, III 1959, 3, P.L.G. Benoit (2 MRAC, 1 MNHW); Kwango–Ngowa, 15 X 1937, 1, J. Martens ( IRSN) ; Libenge Mawuya , 14 IX 1947, 1, R. Cremer & M. Neuman ( IRSN) ; Mandungu , 25 XI 1912, 1, R. Mayné ( MRAC) ; Maniema , Kindu, 26 III 1918, 1, R. Mayné ( MRAC) ; Mondombe , X 1912, 1, R. Mayné ( MRAC) ; Mongbwalu , VII 1938, 1, Mme Scheitz ( MRAC) , IX 1939, 1, Mme Lepersonne ( MRAC) ; Sankuru , Komi, I 1930, 1, 2 I 1930, 1, 8 III 1930, 1, J. Ghesquière ( MRAC) ; Stanleyville, n. Kilo, 1, L. Burgeon ( MRAC) ; Stanleyville , Ongoka, riv. Lowa, IV–IX 1952, 1, J. Pantos ( MRAC) ; Uele , Amadi, 31 VII 1914, 1, Rodhain ( MRAC) ; Ubangi , Binga, 5–12 III 1932, 2, 8 III 1932, 1, 12 III 1932, 4, H.J. Brédo ( MRAC, MNHW) ; Wamba, 1936, 1, Degotte ( MRAC) .

EQUATORIAL GUINEA: Mongo , 1946–1948, 1, J. Palau ( MRAC); Nkolentangan, XI 1907 – V 1908, 3, G. Tesmann ( ZMHU) .

GABON: Gabon, 1 (IRSN); Ivinde, 1 (IRSN); Iviroo Haut, Cape Cottes, 1906, 1, J. Gravot (MNHN); between Lambarene and sea coast, 1901, E. Havg (MNHN).

GUINEA: Guinea, 1 (ZMHU).

REPUBLIC OF CENTRAL AFRICA: Fort Sibut, Oubanghi–Chari, 1 (IRSN); Nola, 1 (IRSN); Lobaye River, Congo Francaise, 1 (NMP).

RWANDA: Cyamudongo F., 2°32’S / 28°58E, 1750 m, 20 III 2007, 1, T. Wagner ( TW) .

TANZANIA: Victoria Lake, Ukerewe Is., 3, Conrads (ZMHU).

TOGO: Amedzowe, 1 (ZMHU).

UGANDA: Durro Forest, Toro , 4.400 –4.500 ft., 25–29 X 1911, 4, S. A. Neave ( BMNH) ; Fort Portal , 15 km E Sebitoli, 1400 m, 23 XI–5 XII 1994, 1, M. Snižek ( MS) ; south of Lake George , 3.200 –3.400 ft., 17–19 X 1911, 1, S. A. Neave ( BMNH) ; Kalinzu Forest, Mpungu , 1200–1350 m, VI 1972, 1, H. Gřnget ( ZMC) ; Kisubi , 17 X 1971, 1, H. Gřnget ( ZMC) ; Mabira Forest, Chagwe , 3500–3800 ft., 16–25 VI 1911, 1, S.A. Neave ( BMNH) ; Toro Distr., Ft. Portal, Kibale Forest , V–IX 1992, 1 ( JM) ; Western Ankole , 4.500 –5.000 ft., 10–14 X 1911, 2, S. A. Neave ( BMNH) .

Figures

FIGURE 21. Distribution of Cassida imitatrix.

FIGURE 22. Distribution of Cassida inaequalis (black circles) and Cassida kantnerorum (black diamond).

FIGURE 46. Distribution of Cassida tarda (black circles) and Cassida thomsoni (black diamonds).

FIGURES 63–66. Cassida inaequalis. FIGURES 67–68. Cassida blanda. 63–64, 66–67. Dorsal; 65, 68. Lateral.

FIGURES 51–53. Cassida altiuscula. FIGURES 54–56. Cassida overlaeti. 51–52, 54–55. Dorsal; 53, 56. Lateral.

FIGURES 57–62. Cassida tosta. 57–58, 60–62. Dorsal; 59. Lateral.

FIGURES 69–71. Cassida coagulata. FIGURES 72–74. Cassida irrorata. 69–70, 72–73. Dorsal; 71, 74. Lateral.