Cassida imitatrix 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 : 84-86

Cassida imitatrix Spaeth, 1916

( figs. 21 , 256–258 )

Cassida imitatrix Spaeth, 1916: 47 ; Nummelin & Borowiec, 1991: 14; Borowiec, 1999: 257.

Description. L: 5.05–6.60 mm, W: 4.15–5.20 mm, Lp: 1.80–2.30 mm, Wp: 3.00–3.90 mm, L/W: 1.22–1.31, Wp/ Lp: 1.67–1.83. Body oval, males stouter than females ( figs. 256, 257 ).

Entire body yellow, including head, ventrites and legs ( figs. 256–258 ). Antennal segment 1–6 yellow, last five segments more or less infuscate, occasionally entire antennae yellow.

Pronotum elliptical, with maximum width in the middle, anterior margin regularly convex, sides broadly rounded, no basal corners. Disc convex, slightly bordered from explanate margin except short lateral impressions, without lateral lobes, with hardly marked area above head. Surface of disc shiny, top of disc and sides with fine and sparse punctation, area above head impunctate. Distance between punctures three to five times wider than puncture diameter, interspaces regular. Explanate margin broad, impunctate, shiny, transparent with well visible honeycomb structure.

Base of elytra much wider than base of pronotum, humeral angles distinctly protruding anterad, angulate. Disc strongly convex in profile ( fig. 258 ), with deep postscutellar and principal impressions, sometimes with shallow posterolateral impressions, distinctly elevated in postscutellar area with low and obtuse H–shaped elevation, sutural intervals slightly convex, interspaces on sides of disc slightly convex but surface of disc appears mostly regular. Punctation moderately coarse and moderately dense, along suture and along sides forms more or less regular rows, in impressions and in broad third interval additional irregular punctures, sometimes also fourth interval with few additional punctures, distance between punctures in rows from as wide as to twice wider than puncture diameter. Marginal row distinct, its punctures shallow but distinctly coarser than in central rows. Intervals mostly well marked, as wide as rows except very broad third interval and moderately broad submarginal interval, marginal interval distinct, broad, in humeral part as wide as submarginal interval and two rows combined, no humeral or lateral folds. Explanate margin moderately broad, moderately declivous, in the widest part 4.5 times narrower than disc, surface shiny, with shallow but moderately coarse and dense punctation, appears irregular, transparent with well visible honeycomb structure.

Eyes very large, gena obsolete. Clypeus very broad, approximately 1.5 times as wide as long. Clypeal grooves fine but well marked, runs close to margin to eye then converging in triangle with obtuse top, surface of clypeus, flat shiny with several small setose punctures. Labrum deeply emarginate to 1/4 length. Antennae moderately slim, segments 9–10 slightly longer than wide. Length ratio of antennal segments: 100:50:61:64:61:50:58:56:56:61:103. Segment 3 approximately 1.2 times as long as segment 2 and slightly shorter than segment 4.

Prosternum moderately broad in the middle, strongly expanded apically, area between coxa deeply impressed, shiny, without special sculpture except several very small, setose punctures, expanded apex slightly convex but often with round central impression, shiny, with slightly irregular surface and few small, setose punctures.

Claws with large basal tooth.

Distribution. Sierra Leone, Central Africa east to Ethiopia ( fig. 21 ).

Remarks. A member of the Cassida sulphurago species–group similar only to C. sulphurago . Both species have a moderately large to large body, length of 5.0–7.5 mm, dorsum and ventrites always uniformly yellow, base of elytra moderately to distinctly wider than pronotum, rows of punctures completely regular but often with some intervals with additional irregular punctures, and elytral sculpture absent or indistinct, limited to slightly elevated intervals on top of disc. Cassida sulphurago differs in the pronotum widest in anterior third with sides subangulate (fgs. 259, 256) and in having simple claws. Small specimens of C. imitatrix are similar to C. benaadirensis but it differs in the base of elytra slightly wider than pronotum, pronotum with less regularly rounded sides, widest slightly in front of the middle, punctation of elytra more regular, intervals on slope and posterolateral parts of disc without additional punctures ( figs. 262, 263 ). Cassida sulphurea , the third species of C. sulphurago species–group, distinctly differs in a more convex elytral disc (fig. 265), pronotal sides less broadly convex, elytral punctation completely regular without additional irregular punctures on some intervals and simple claws (fig. 264).

Type examined. Syntype: [ DEMOCRATIC REPUBLIC OF CONGO (ZAIRE)]: Beni, Moera ( MRAC) .

Other specimens examined. CAMEROON: Buea , 600 m, XI 1957, 1, 1000 m, XII 1957, 1, W. Hartwig ( MKB) ; Camerun merid., 1 ( HNHM) ; Djoungolo , Nkongzok, 11 II 1963, L. Segers ( ZSM) ; Kamerunberg , 5 km S Muëli, 580 m, 21 II 1958, 1, H. Knorr ( ZSM) ; Mt. Balmayo , 1, Barga ( MRAC) ; Okola , Ebongsi –r. Mbanize, 19 VII 1963, 1, L. Segers ( ZSM) .

DEMOCRATIC REPUBLIC OF CONGO (ZAIRE): Albert Nat. Park , Mont Hoyo, grotte Kabambi, 1260 m, 1 VIII 1955, 1, P. Vanschuytbroeck ( MRAC) ; Albert Nat. Park , Mont Hoyo, grotte Yolohafiri, 1030 m, 19–20 VII 1955, 1, P. Vanschuytbroeck ( MRAC) ; Albert Nat. Park , Secteur Nord , riv. Byangolo, affl. g. Djilube, 1320 m, 19 IX 1956, 3, P. Vanschuytbroeck ( MRAC, MNHW) ; Albert Nat. Park , riv. Molidi, piste Watalinga, 1210 m, 18 IX 1956, 1, P. Vanschuytbroeck ( MRAC) ; Albert Nat. Park , Secteur Nord , Musinini, affl. Byangolo, 1100 m, 1 II 1957, 1, P. Vanschuytbroeck ( MRAC) ; Bambesa , IV 1939, 1, J. Vrydagh ( MRAC) ; Ituri , 1946, 2 ( LS) ; Kindu , 1, L. Burgeon ( MRAC) .

ETHIOPIA: Arsi Reg. , Wondo Genet, 1890 m, VI 1990, 4, Werner ( DS, MNHW) ; Illubabor Prov. , 15 km NW Chora, 1600 m, VI 1973, 1, G. de Rougemont ( MNHW) ; Ilubabor Pr., Tépi , Masha, 8–9 V 2003, 1, B. Malec ( FK) ; Kaffa , Anderaccia near Ammaia, 1650 m, 26 X 1973, 1, Brignoli ( DS) .

KENYA: Kakamega Forest , 0.27 N / 34.88 E, 1600 m, X 2001, 2, I–II 1902, 2, W. Freund ( TW) ;

RWANDA: Cyamudongo, 1700 m, X 1993, 1 ex. Carapa grandiflora (Meliaceae) , T. Wagner ( TW); Cyangugu, Nyakabuye, 1–30 XII 1982, 1, H. Mühle ( HK).

SIERRA LEONE: Loma Mts. , farmland/mosaic forest 9°07’47”N, 11°05’24”W, 420 m, 11–15 VI 2016, 6, Takano, Miles & Goff leg. (4 BMNH, 2 LS); 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) .

SUDAN: Didinga , Nagichot , 1, D.H. Carpenter ( MM); Equatoria, Lotti forest, 14–17 III 1963, 1, R. Linnavuori ( ZMUH) .

UGANDA: Fort Portal , 15 km E Sebitoli, 1400 m, 23 XI–5 XII 1994, 2, M. Snižek ( MS) ; Kibale Forest , 12–13 IX 1983, 1, M. Nummelin ( MNHW) , 16 XII 1984, 1, 19 I 1985, 1, 14 II 1985, 2, 28 IV 1965, 1, M. Nummelin ( ZMUH) .

Figures

FIGURE 21. Distribution of Cassida imitatrix.

FIGURES 256–258. Cassida imitatrix. 259–261. Cassida sulphurago. 256–257, 259–260. Dorsal; 258, 261. Lateral.

FIGURES 262–263. Cassida benaadirensis. 264–265. Cassida sulphurea. 262, 264. Dorsal; 263, 265. Lateral.