Cassida humerosa Spaeth, 1902

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 : 81-83

Cassida humerosa Spaeth, 1902

( figs. 20 , 86–91 )

Cassida humerosa Spaeth, 1902: 455, 1943: 61 ; Shaw, 1955: 237, 1961: 30, 1972: 75; Borowiec, 1986: 806, 1999: 256; Nummelin & Borowiec, 1991: 14.

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

Cassida humeralis [sic]: Spaeth, 1916: 41.

Cassida imbellis Spaeth, 1924: 358 ; Borowiec, 1986: 806 (as syn. of humerosa ).

Cassida humerosa imbellis: Spaeth, 1925 a: 5 .

Cassida humerosa ab. imbellis: Spaeth, 1943: 61 ; Shaw, 1955: 237.

Cassida humerosa ssp. Wittei Spaeth, 1943: 62; Borowiec, 1999: 256 (as syn. of humerosa ).

Description. L: 4.25–5.80 mm, W: 3.70–4.80 mm, Lp: 1.45–1.95 mm, Wp: 2.70–3.70 mm, L/W: 1.15–1.26, Wp/ Lp: 1.82–2.0. Body from almost circular to short–oval, males slightly stouter than female ( figs. 86, 87, 89–94 ).

Extremely variable species. In typically coloured specimens pronotum uniformly yellow, scutellum yellow, elytral disc with marble pattern of mixed yellow and brown to black, postscutellar elevation with dark elongate spot, top of disc with predominate yellow, sides with predominate brown to black, explanate margin yellow with broad humeral brown to black spot extending almost to lateral margin of elytra except extreme narrow yellow margin ( figs. 87, 88 ). In extreme pale form dorsum uniformly yellow ( fig. 89 ), in extreme dark form pronotal disc black, elytral disc completely black and explanate margin of elytra with broad black humeral spot but scutellum always yellow ( fig. 94 ). Between extreme forms all intermediate occur: disc with only few to several brownish spots but explanate margin without humeral spot, or entire elytral disc reddish and explanate margin of elytra with reddish humeral spot ( fig. 86 ), or top of disc yellow with only elongate brown to black spot on postscutellar elevation but sides of disc broadly surrounded by brown to black ( fig. 91 ), sometimes disc of elytra with predominantly black marble pattern but explanate margin of elytra without humeral spots ( fig. 90 ) or disc of elytra with predominantly yellow marble pattern but with distinct humeral spots, or pronotal and elytral disc black but explanate margin without humeral spot ( fig. 92 ). Head yellow, prosternum from yellowish brown to black, meso– and metasternum black, abdomen at least in the middle black surrounded by yellow. Legs yellow.Antennae usually uniformly yellow, last segment sometimes slightly infuscate.

Pronotum regularly elliptical, with maximum width in the middle, anterior margin regularly convex, sides broadly rounded, no basal corners.Area above head only slightly impressed, disc indistinctly bordered from explanate margin except short lateral impression. Surface of disc shiny to alutaceous (especially in dark coloured specimens) with fine and sparse punctation, distance between punctures mostly two to three times wider than puncture diameter. In some specimens surface of disc with very fine irregular striation but surface appears mostly regular. Explanate margin broad, impunctate, shiny to alutaceous, transparent with well visible honeycomb structure.

Base of elytra much wider than base of pronotum, humeral angles moderately protruding anterad, subrounded to subangulate. Disc regularly convex in profile ( fig. 88 ), with shallow postscutellar and principal impressions and low but well marked H–shaped postscutellar elevation, second interval more or less elevated, often also central part of fourth interval elevated, in specimens with marble pattern yellow parts usually form relief . Punctation coarse, arranged in completely regular rows, postscutellar impressions often with additional irregular punctures. Punctures in rows dense, distance between punctures mostly narrower than puncture diameter. Marginal row distinct, its punctures not or only slightly coarser than punctures in central rows. Intervals in sutural area as wide as rows on sides narrower than rows to linear, marginal interval narrow, as wide as submarginal interval and submarginal row combined, usually without humeral folds but with short lateral fold. Explanate margin broad, moderately declivous, in the widest part 3–3.5 times narrower than disc, surface from slightly alutaceous to slightly shiny with shallow punctation and slightly elevated interspaces, appears from almost regular to slightly irregular, transparent with well visible honeycomb structure, only black humeral spots with coarse, shallow punctures.

Eyes very large, gena obsolete. Clypeus moderately broad, approximately 1.2 times as wide as long. Clypeal grooves fine but well marked, in basal half runs close to margin of eye then converging in arch or triangle with obtuse top, surface of clypeus flat, its surface shiny with few very small, setose punctures. Labrum narrowly emarginate to 1/4 length. Antennae slim, segments 9–10 approximately 1.7 times as long as wide. Length ratio of antennal segments: 100:58:73:64:67:55:64:48:58:64:115. Segment 3 approximately 1.3 times as long as segment 2 and 1.1 times as long as segment 4.

Prosternum moderately broad in the middle, strongly expanded apically, area between coxa more or less canaliculate, shiny, along sides with row of hairy punctures, surface often with tiny oblique wrinkles, expanded apex convex in the middle, impressed laterally, without special sculpture except several hairy punctures.

Claws with large basal tooth.

Distribution. Equatorial part across Africa ( fig. 20 ).

Remarks. A member of the Cassida lacrymosa species–group. The most variable species within the group. The typical form has only a humeral spot on the explanate margin of elytra ( fig. 87 ) similar to C. camerunensis but it differs in the elytral sculpture less marked, second interval obtusely convex only in posterior third, punctation smaller, interspaces not convex, surface of disc mostly regular; punctation of explanate margin of elytra very shallow (fig. 95). The elytral pattern in C. camerunensis does not vary. Forms of C. humerosa with a reddish elytral disc and humeral spots ( fig. 86 ) are unique and not similar to any African species. Forms of C. humerosa with a completely black elytral disc ( figs. 92–94 ) differ from other African species of the C. lacrymosa species–group in having a yellow scutellum. Forms of C. humerosa with a black marble pattern ( fig. 90 ) differ from other such coloured species of the C. lacrymosa species–group in having a more circular and larger body with length of up to 5.8 mm (up to 5.2 mm, but usually below 5.0 mm in other species).

Types examined. Syntype of Cassida humerosa Spaeth, 1902 : [ DEMOCRATIC REPUBLIC OF CONGO (ZAIRE)]: Zambi, C.L. Haas ( MM) ; syntype of Cassida humerosa Spaeth, 1902 : [ DEMOCRATIC REPUBLIC OF CONGO (ZAIRE)]: Chiloango, M. Tschoffen ( IRSN) ; syntype of Cassida imbellis Spaeth, 1924 : [ TANZANIA]: Victoria Njansa ( MM) ; syntype of Cassida imbellis Spaeth, 1924 : [ UGANDA]: Kampala, 15 XI 1917 ( BMNH) .

Other specimens examined. CAMEROON: Bipindi , III 1897, 1, G. Zenker ( ZMHU) ; Cameroon , 1 ( DEI) ; Djoungolo , Oman, r. Nkelkongo, 16 IX 1963, 2, L. Segers ( ZSM) ; Djoungolo , Villa Carde n. Nyong, 27 VIII 1963, 1, L. Segers ( ZSM) ; Kamerunberg , 5 km S Muëli, 580 m, 21 II 1958, 1, H. Knorr ( ZSM) ; Mfou , Nkolusala, r. Nsala, 27 VIII 1963, 1, L. Segers ( ZSM) ; Mueli , Mt. Kamerun, 600 m, II 1958, 3, W. Hartwig ( MKB) ; Nkolbison , Yaounde–Bi, 11 II 1963, 2, 16 II 1963, 1, 20 V 1963, 1, L. Segers ( ZSM, MNHW) ; Okola , Ebongsi, r. Mbanize, 17 IX 1963, 1, L. Segers ( ZSM) ; Yaunde , 31 III 1923, 1 ( CMNH) ; Okola , Nkong, r. Yégué, 14 VIII 1963, 1 on Setaria megaphyllia Beauv., L. Segers (MNHW) .

DEMOCRATIC REPUBLIC OF CONGO (ZAIRE): Albert Nat. Park , Kabasha, 14 II 1934, 2, de Witte ( MRAC) ; Albert Nat. Park , Kivu, N’Dalage, 8 VIII 1935, 1, H. Damas ( MRAC) ; Albert Nat. Park , Mont Hoyo, sur plantes basses, 1280 m, 7–15 VII 1955, 11, P. Vanschuytbroeck (8 MRAC, 3 MNHW) ; Albert Nat. Park , Mont Hoyo, grotte Yolohafiri, 10130 m, 25–28 VII 1955, 1, P. Vanschuytbroeck ( MRAC) ; Albert Nat. Park , Mont Hoyo, grotte Saga–Saga, 1160 m, 11–14 VII 1955, 1, P. Vanschuytbroeck ( MRAC) ; Albert Nat. Park , Mutsora, 1939, 7, Hackars (5 MRAC, 2 MNHW) ; Albert Nat. Park , Ngama, lac Bluniu, 3–10 IV 1935, 1, H. Damas ( MRAC) ; Albert Nat. Park , r. Ondo, affl. Rutshuru, 30 VII 1935, 1, H. Damas ( MRAC) ; Albert Nat. Park , Rumangabo, riv. Bugombwa, 9 IV 1945, 1, G.F. de Witte ( MRAC) ; Albert Nat. Park , Rutshuru n. Molindi, 1000 m, 15 V 1934, 1, de Witte ( MRAC) ; Albert Nat. Park , W Ruwenzori, 1200–1500 m, IV 1937, 1, Hackars ( MRAC) ; Albert Nat. Park , Ruwenzori, Mutawanga, 1000–1300 m, II–III 1937, 1, Hackars ( MRAC) ; Albert Nat. Park , Rweru, Volc. Mikeno, 2400 m, 26–27 VII 1934, 1, de Witte ( MRAC) ; Albert Nat.Park , Rwindi, 1000 m, 20–24 XI 1934, 3, de Witte ( IRSN, MRAC) ; Albert Nat. Park , Secteur Nord , riv. Byangolo, affl. g. Djilube, 1320 m, 19 IX 1956, 5, P. Vanschuytbroeck (4 MRAC, 1 MNHW) ; Albert Nat. Park , Secteur Nord , riv. Lutakira, affl. dr. Semliki, 910 m, 10 X 1957, 1, P. Vanschuytbroeck ( MRAC) ; Albert Nat. Park , Secteur Nord , riv. May ya Moto, affl. g. Talya, 1180 m, 9 V 1957, 1, 17 V 1957, 1, P. Vanschuytbroeck ( MRAC) ; Albert Nat. Park , Secteur Nord , riv. Musinini, affl. Byangolo, 1225 m, 14 IV 1958, 1, P. Vanschuytbroeck ( MRAC) ; Albert Nat. Park , Secteur Nord , Ngokoi, affl. g. Talya, 1180 m, 11 IX 1957, 1, 1100 m, 29 V 1958, 1, P. Vanschuytbroeck ( MRAC) ; Albert Nat. Park , Secteur Nord , source riv. Rugetsi, affl. dr. Semliki, 1380 m, 17 X 1956, 1, P. Vanschuytbroeck ( MRAC) ; Albert Nat. Park , Sommet Bishoke, II 1935, 1, de Witte (holotype of wittei, MRAC) ; Arebi , Bondo–Moto, 28 VII 1925, 1, H. Schouteden ( MRAC) ; Bambesa , 10 IX 1933, 1, J. Leroy ( MRAC) ; Bas Uele , Matale, 15 VII 1958, 1 ( FMNH) ; Beni , 2, Lt. Borgerhoff ( MRAC) ; Beni n. Lesse, VII 1911, 3, Murtula ( MRAC) ; Dima , 22 IX 1908, 1, A. Koller ( MRAC) ; Equateur , Bangu, XI 1927, 1, R. Mayné ( MRAC) ; Garamba Nat. Park , Mt Embe, 20 IV 1952, 5, De Saeger ( IRSN, MRAC) ; Haut Uele , Moto, II 1922, 1, 1923, 1, L. Burgeon ( MRAC) ; Haut Uele , Watsa, 1922, 1, L. Burgeon ( MRAC) ; Kasai , Ipamu, 1922, 1, P. Vanderijst ( MRAC) ; Kasai , Ngombe, 17 XI 1921, 2, H. Schouteden ( MRAC) ; Kasongo , Niembo, VI 1918, 1, R. Mayné ( MRAC) ; Kibali–Ituri , Nikanga, 2 II 1940, 3, A. Lepersonne ( MRAC) ; Kimuele , 8 II 1923, 1, A. Collart ( IRSN) ; Kiniati–Zobe , XII 1915, 1, R. Mayné ( MRAC) ; Kivu , Luvungi, XII, 1, L. Burgeon ( MRAC) ; Kivu , Masisi, 1, A. Collart ( IRSN) ; Kivu , Sake, 14 III 1936, 1, L. Lippens ( MRAC) ; Kiwu–Ituri , 1 ( LS) ; Lac Albert , foret de Kawa, 29 IV 1929, 1, A. Collart ( IRSN) ; Lemfu n. Kimpese, 1, P. Vanderijst ( MRAC) ; Lulua , Kapanga, VIII 1932, 1, F. Overlaet ( MRAC) ; Mayumbe , 1931, 2, P. Vanderijst ( MRAC) ; Mayumbe , Kursu, 15 XII 1923, 1, A. Collart ( MRAC) ; Mayumbe , Tshela, 13–27 II 1916, 1, R. Mayné ( MRAC) , III 1964, 1, A. Fain ( MRAC) ; Mayumbe–Zobe , I 1916, 1, R. Mayné ( MRAC) ; Mongbwalu , Kilo, 1937, 1, Mme Scheitz ( MRAC) ; Mongende , 13 IV 1921, 1, 12 VI 1921, 1, H. Schouteden ( MRAC) ; Rutshuru , I 1937, 1, IV 1937, 1, V 1937, 1, J. Ghesquière ( MRAC) ; Rutshuru , Kilinga, I 1936, 1, L. Lippens ( MRAC) ; Rutshuru , Kivu, 23 VI 1934, 1, 2 VII 1935, 2, 3 VII 1935, 1, 11 VII 1935, 1, de Witte ( IRSN) ; Ruwenzori , N Alb. – Edw. See, II 1908, 1 ( ZMHU) ; Seke Banza , Mayumbe, XI 1924, 1, A. Collart ( MRAC) ; Tumbalunga , Dibaya, 8 IX 1930, 1, de Witte ( MRAC) ; Uele , Dingila, VI 1933, 1, H.J. Brèdo ( MRAC) .

EQUATORIAL GUINEA: Mongo , 18 V 1942, 1, J. Palau ( MCNB); Nkolentangan, XI 1907 – V 1908, 1, G. Tessmann ( ZMHU) .

ETHIOPIA: Belleta forest , 13–14 VI 1963, 2, R. Linnavuori ( ZMUH) ; Kaffa , Bonga, 16 II 1974, 1, R. Linnavuori ( ZMUH) ; Illubabor , Bedele–Metu, 4 V 2002, 1, K. Werner ( MS) ; Illubabor Prov. , 15 km NW Ihora, VI 1973, 1, G. de Rougemont ( MRAC) ; Kaffa , Bebeka, 7 V 2002, 5, 10 V 1999, 2, K. Werner ( MS) ; Kaffa , Gore–Tepi, 6 V 2002, 2, K. Werner ( MS) .

GHANA: Ashanti regin, Juaben , 19 II 1967, 1, S. Endrödy – Younga ( HNHM) .

GUINEA: Nzerekore , II 1920, 2, P. Chabanaud ( MNHN) .

IVORY COAST: Daloa , 25 VIII 1965, 1, C. Besnard ( BB); Haute Huon, env. Danane, 1910, 1, A. Chevalier ( MNHN) .

KENYA: Kakamega Forest St. , 3–6 IV 1981, 1, J. Krikken et al. ( NNML) , 1800 m, 30 I 1992, 1, O. Merkl and G. Várkonyi ( HNHM) ; Kakamega Forest N.P., Bujango, Udo’s camp, 1603 m, 17 I 2004, 1, F. Haas ( SMNS) ; M’laba Forest , 2 II 1979, 5, T. Palm ( LU) ; Yala R., sedge of Kakamuga Forest , 4800–5300 ft., 21–28 V 1911, 1, S.A. Neave ( BMNH) .

NIGERIA: Yankari Game Res., Gaji river , 15 VIII 1978, 1, A. Demeter ( HNHM) .

REPUBLIC OF CENTRAL AFRICA: Fort Sibut, Oubanchi–Chari, 1 (NMP); M’Baiki, 1919, 1, Pitard (MNHN).

REPUBLIC OF CONGO: Sibiti nr. Zanzi, 1, 28 XI 1963, 1, Balogh & Zicsi ( HNHM); Sibiti, Irho, 27 XI 1963, 1, Balogh & Zicsi ( HNHM) .

RWANDA: Cyamudongo , 1700 m, X 1993, 3, T. Wagner ( TW) ; 20 km SE Cyangugu, 19 XII 1985, 1, H. Mühle ( HK); Cyangugu , Nyakabuye , 26 XII 1985, 1, H. Mühle ( HK); Gitarama, terr. Nyanza, II 1953, 1, P. Basilevsky ( MRAC) ; Gîte de Nkuli , 17 III 1936, 1, L. Lippens ( MRAC) ; Muhavura , 2100 m, 28 I 1953, 1, P. Basilevsky ( MRAC) ; Ruhengeri , 1900 m, 27 I 1953, 1, P. Basilevsky ( MRAC) ; Rusumo , Ibanda, Makera, X 1993, 2, T. Wagner ( TW) .

SIERRA LEONE: Loma Mts. , farmland/mosaic forest 9°07’47”N, 11°05’24”W, 420 m, 11–15 VI 2016, 8, Takano, Miles & Goff leg. (5 BMNH, 3 LS); Loma Mts., closed canopy forest, 9°10’35”N, 11°05’25”W, 1050 m, 7–10 VI 2016, 2, Takano, Miles & Goff leg. ( BMNH) .

SUDAN: Equatoria , Lotti forest, 14–17 III 1963, 4, R. Linnavuori ( ZMUH) ; Imatong Mts. , Gilo, 18–24 III 1963, 2, R. Linnavuori ( ZMUH) ; Yambio , 18–25 IV 1963, 1, R. Linnavuori ( ZMUH) .

TANZANIA: Nyassa–see, Langenburg, 1898, 1, Fülleborn (ZMHU).

TOGO: Bismarckburg , 1 V–23 VI 1893, 1, 24 VI–9 X 1893, 1, L. Conradt ( ZMHU) .

UGANDA: Distr. Busoga , env. Jinja, I–III 1968, 1, J. Rwabuneza ( MRAC) ; S of George Lake , 3200–3400 ft., 17– 19 X 1911, 1, S.A. Neave ( BMNH) ; Fort Portal , 15 km E Sebitoli, 1400 m, 23 XI–5 XII 1994, 1, M. Snižek ( MS) ; SW of Hioma, Rwera env., 30 XI 2001, 1, M. Snižek ( MS) ; Kabarole, Kibale Forest N.P., Kanyawara , 0°33’N, 30°21’E, 1200–1400 m, VIII 1997, 1, Chr. Häuser leg. ( SMNS ; Kalinzu Forest , X 1937, 2, T. H. E. Jackson ( BMNH) ; Kibale Forest , 18 IX 1985 – 12 IX 1986, 112, M. Nummelin ( ZMUH) ; Mabira , 1 ( NMP) , X 1938, 1 ( LS) , 4, R.A. Dummar ( IRSN) ; Mubende env., 19–22 XI 2001, 1, M. Snižek ( MS) ; Ruwenzori Mts. , Ibanda, 1900 m., 4 I 1996, 1, I. Yarom & A. Freidberg ( TAU) ; Seziwa R. – Kampala road, 3500–3750 ft., 27–31 VIII 1911, 2, S.A. Neave ( BMNH) .

URUNDI: Bururi, 1800–2000 m, 5–12 III 1953, 2, P. Basilevsky ( MRAC) .

Figures

FIGURE 20. Distribution of Cassida heroni (black circles) and Cassida humerosa (black diamonds).

FIGURES 86–91. Cassida humerosa. 86–87, 89–91. Dorsal; 88. Lateral.

FIGURES 92–94. Cassida humerosa. FIGURES 95–96. Cassida camerunensis. 92–95. Dorsal; 96. Lateral.