Cassida eluta Boheman, 1862

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 : 64-66

Cassida eluta Boheman, 1862

( figs. 17 , 193–195 )

Cassida eluta Boheman, 1862: 319 ; Gemminger & Harold, 1876: 3653; Spaeth, 1939: 18; Borowiec, 1999: 250.

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

Cassida cherenica Spaeth, 1917: 433 ; Borowiec, 1999: 242, n. syn.

Description. L: 4.30–4.70 mm, W: 3.20–3.50 mm, Lp: 1.60–1.70 mm, Wp: 2.70–2.90 mm, L/W: 1.34–1.35, Wp/ Lp: 1.62–1.71. Body oval, widest in the middle, on sides only slightly rounded ( figs. 193–194 ).

Pronotum and scutellum pale yellow. Elytra pale yellow, disc with brown pattern of small brown spots. Always is present spot on postscutellar elevation and two small spots in and behind the middle of elevated second interval. In the palest specimens also few punctures with brownish areola but disc appears mostly yellow. In the darkest specimens most punctures have brown areola, some areolae connected and form small , irregular patches thus elytral disc appears distinctly maculate ( figs. 193, 194 ). Clypeus in the palest specimens uniformly yellow, in spotted specimens basal margin and corners brown but the brown colour occupies not more than 1/3 of surface of clypeal plate. Ventrites in the palest specimens mostly yellow only prosternum between coxae and basal part of metasternum brownish. In spotted specimens entire pro–, meso–, and metasternum brownish except yellow epimera and episterna. Abdomen always yellow. Antennae and legs completely yellow.

Pronotum elliptical, with maximum width in the middle, sides broadly rounded. Disc slightly convex, on sides separated from explanate margin by short furrow. Surface of disc glabrous, smooth and shiny. Explanate margin glabrous, smooth, shiny, transparent with well visible honeycomb structure.

Base of elytra moderately wider than base of pronotum, basal margin of disc with very small black crenulation, humeral angles moderately protruding anterad, distinctly angulate to subacute. Disc only slightly convex in profile, almost depressed, with top of convexity in postscutellar point ( fig. 195 ), with well marked scutellar and principal impressions, also on sides of disc punctures tend to form shallowly impressed fields. Postscutellar area with distinct H–shaped elevation, in front surrounding postscutellar impressions, behind prolongates to slightly elevated second intervals. Punctation moderately coarse, regular but appears slightly irregular because punctures tend to group 2–3 together with larger and partly convex intervals between groups. Marginal row distinct, with dense punctures, as coarse as punctures in lateral rows. Intervals narrow, on sides of disc linear, only intervals 1 and mostly and interval 3 on slope well marked, interval 2 on entire length and interval 3 on slope slightly convex. Regularity of intervals disturbed by arrangement of punctures and elevated interspaces. Marginal interval well marked on entire length, broad, in anterior half almost twice wider than lateral intervals, with well marked humeral and lateral folds. Surface of intervals glabrous, smooth and shiny. Explanate margin moderately declivous, broad, in the widest part five times narrower than disc. Surface of explanate margin very shallowly punctate, appears almost regular, glabrous, shiny, transparent with well marked honeycomb structure.

Eyes large, gena obsolete. Clypeus moderately broad, 1.14 times as wide as log, frontal grooves very fine, converging in triangle. Surface of clypeal plate flat or with shallow impression apically, glabrous and shiny with several very small setose punctures. Part of clypeus between clypeal triangle and margin of eyes with a row of long hair. Labrum distinctly emarginate to 1/3 length. Antennae slim but short, segments 9–10 slightly wider than long. Length ratio of antennal segments: 100:64:86:75:64:57:50:50:54:57:107. Segment 3 approximately 1.34 times as long as segment 2 and 1.15 times as long as segment 4.

Prosternal process broad, moderately impressed along lateral margins, very broad apically, along sides with row of setose punctures, central part of rhomboidal apex convex, with few setose punctures.

Claws with large basal tooth.

Distribution. Ethiopia, Eritrea and Tanzania ( fig. 17 ).

Remarks. We have examined the holotype of Cassida eluta Boheman, 1862 and two syntypes of Cassida cherenica Spaeth, 1917 and both taxa are conspecific.

A member of the Cassida lacrymosa species–group. It is one of the smallest and the most elongate species of the group with length below 4.8 mm and L/W: 1.34–1.35. The immaculate pronotal disc and predominantly yellow elytra with scarce pattern of small brown spots place C. eluta close only to C. voiensis and especially to C. namibiensis . The first species differs in elytral pattern on elytral sides reduced only to dark centres of punctures andwith central part of disc without pattern except spot on postscutellar elevation and few very small reddish brown spots in posterior half of disc. The second species differs in finer elytral punctation, with distance between punctures in lateral rows mostly as wide as or only slightly smaller than puncture diameter and sides of elytra slightly less rounded; both species are broadly separated geographically. Cassida eluta occurs only in north-eastern Africa south to northern Tanzania, while C. nambiensis is known only from Namibia.

Type examined. Holotype of Cassida eluta Boheman, 1862 : [ ETHIOPIA]: Abyssin., Thorey ( NRS); two syntypes of Cassida cherenica Spaeth, 1917 : [ ERITREA] Erithraea, Cheren ( MM).

Other specimens examined. ETHIOPIA: Sabata , 25 km S Addis –Ababa, 2000 m, 28 VII 1988, 1, L. Medvedev ( MNHW); Tigra, 1 ( MNHW) .

TANZANIA: Kirumba n. Mwansa, 6 IV 1916, 1, Holtz ( MM) .

Figures

FIGURE 17. Distribution of Cassida eluta (black circles), Cassida franklinmuelleri (black diamonds) and Cassida fuscosignata (black square).

FIGURES 193–195. Cassida eluta. 196–198. Cassida voiensis. 193–194, 196–197. Dorsal; 195, 198. Lateral.