Cassida nigeriana, Borowiec & Świętojańska, 2022

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 : 115-116

Cassida nigeriana sp. nov.

( figs. 26 , 212–213)

http://zoobank.org/ urn:lsid:zoobank.org:act:DDAFB59C-28A5-4454-B385-2312067C8129

Etymology. Named after its terra typica. It was collected only in one locality in Nigeria.

Description. L: 4.45–4.70 mm, W: 3.40–3.60 mm, Lp: 1.55–1.60 mm, Wp: 2.55–2.70 mm, L/W: 1.27–1.32, Wp/Lp: 1.59–1.69. Body short–oval (fig. 212).

Pronotum and scutellum pale yellow. Elytral disc yellow with ochraceous to pale brown pattern forming spot in postscutellar impressions, small spot behind the H–shaped elevation, band along sides of disc, and transverse bands slightly behind the middle of disc and on slope (fig. 212). In aberrations the pattern reduced to spots in postscutellar impressions and behind the H–shaped elevation, and transverse spots in position of transverse bands in typically coloured specimens, in such cases lateral bands obsolete. Head, ventrites, legs and antennae completely yellow.

Pronotum elliptical, with maximum width in the middle, sides rounded. Disc slightly convex, on sides separated from explanate margin by short impressions, area above head shallowly impressed. Surface of disc, shiny with fine and sparse punctation, interspaces mostly larger than puncture diameter. Explanate margin, smooth, shiny, transparent with well visible honeycomb structure.

Base of elytra slightly to moderately wider than base of pronotum, basal margin of disc with very small black crenulation, humeral angles moderately protruding anterad, angulate. Disc only slightly convex in profile, almost depressed (fig. 213), with well marked scutellar and principal impressions and distinct but low and obtuse Hshaped elevation and few short elevations on sides of disc, in front surrounding postscutellar impressions, behind prolongates to slightly elevated second intervals. Punctation moderately coarse, mostly forms regular rows, distance between punctures from slightly narrower to slightly larger than puncture diameter. Marginal row distinct, with dense punctures, as coarse as punctures in lateral rows. Intervals narrow, mostly as wide as or slightly wider than rows. Marginal interval well marked on entire length, broad, in anterior half as wide as submarginal interval and two submarginal rows combined, without humeral but with short lateral folds. Surface of intervals microreticulate but appears shiny. Explanate margin moderately declivous, broad, in the widest part five times narrower than disc. Surface of explanate margin shallowly but densely punctate, appears slightly irregular, shiny, transparent with well marked honeycomb structure.

Eyes very large, gena obsolete. Clypeus moderately broad, 1.2 times as wide as long, frontal grooves very fine, run close to margin of eye, on top converging in obtuse angle. Surface of clypeal plate flat, shiny with few very small setose punctures. Labrum shallowly emarginate. Antennae slim, segments 9–10 slightly longer than wide. Length ratio of antennal segments: 100:47:60:60:57:43:57:53:53:63:117. Segment 3 approximately 1.3 times as long as segment 2 and as long as segment 4.

Prosternal process moderately broad, strongly expanded apically, area between coxa impressed, shiny, without special sculpture, rhomboidal apex only slightly convex in central part, shiny, with few very small, setose punctures.

Claws simple.

Distribution. Nigeria ( fig. 26 ).

Remarks. A distinct species with no close relatives in Africa. Its elytral pattern is close only to the pattern of Cassida minutissima but it differs in very small size with length 3.20-3.40 mm (in C. nigeriana L 4.45–4.70 mm), claws with basal tooth and pattern reddish brown not forming a solid stripe in the posthumeral area ( figs. 210, 211 ) while in C. nigeriana claws are simple and the elytral pattern is reddish and forms a solid stripe in the posthumeral area (figs. 212, 213). Both species are separated geographically as C. minutissima is known only from Somalia while C. nigeriana only from Nigeria.

Types examined. Holotype and one paratype: [ NIGERIA]: Nigeria / Plateau State / 1300 m // Jos, W. Park / 7.5.1973 / leg. P. Beron ( MNHW); paratype: [ NIGERIA] Jos / 7.X.55 // Exped. Mus. G. Frey / Nigeria–Kamerun / Bechyne 1955.56 ( NMB); paratype: [ NIGERIA] Jos / 9.X.55 // Exped. Mus. G. Frey / Nigeria–Kamerun / Bechyne 1955.56 ( NMB).

Figures

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

FIGURES 210–211. Cassida minutissima. 212–213. Cassida nigeriana. 210, 212. Dorsal; 211, 213. Lateral.