Cassida minutissima, 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 : 111-112

Cassida minutissima sp. nov.

( figs. 28 , 210–211 )

http://zoobank.org/ urn:lsid:zoobank.org:act:F59CA244-3887-4FE6-94E2-0E692F7A83F5

Etymology. Named after its very small size.

Description. L: 3.20–3.40 mm, W: 2.60–2.65 mm, Lp: 1.25–1.30 mm, Wp: 2.20–2.30 mm, L/W: 1.23–1.28, Wp/Lp: 1.73–1.77. Body short–oval ( fig. 210 ).

Pronotum and scutellum pale yellow. Elytra pale yellow, disc with brown pattern of small brown spots: small spot on postscutellar elevation and small spots in the middle of elevated second interval, most punctures in basal part of disc with brownish areola, brown areolate punctures along sides of disc and on slope form U–shaped irregular figure which in half of disc forms and prolongation to spots on second interval thus sometimes across middle of disc runs incomplete transverse band ( fig. 210 ). Clypeus yellow, prosternum uniformly yellow or infuscate in anterior part, metasternum from uniformly yellow to pale brown, abdomen always yellow. Legs and antennae yellow, last antennal segment more or less infuscate.

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 smooth, shiny, transparent with well visible honeycomb structure.

Base of elytra moderately wider than base of pronotum, humeral angles moderately protruding anterad, distinctly angulate. Disc only slightly convex in profile, almost depressed ( fig. 211 ), with top of convexity in postscutellar point, with well marked scutellar and principal impressions and distinct H–shaped elevation, in front surrounding postscutellar impressions, behind prolongates to slightly elevated second intervals, sides of disc with two small elevations. Punctation moderately coarse, regular but appears slightly irregular because punctures tend to group 2–3 together with larger and partly convex intervals between groups especially on top of disc, in lateral rows punctures almost touching each other. Marginal row distinct, with dense punctures, smaller than punctures in lateral rows and slightly elongate. Intervals narrow, on sides of disc linear, only intervals 1 and 2 approximately as wide as rows. Regularity of intervals partly 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 indistinctly marked humeral and distinctly marked lateral folds. Surface of intervals smooth and shiny. Explanate margin moderately declivous, broad, in the widest part 4.5 times narrower than disc. Surface of explanate margin very shallowly punctate, appears slightly irregular, glabrous, shiny, transparent with well marked honeycomb structure.

Eyes large, gena obsolete. Clypeus moderately broad, approximately as wide as log, frontal grooves very fine, converging in triangle. Surface of clypeal plate flat or with shallow impression apically, shiny with few very small setose punctures. Part of clypeus between clypeal triangle and margin of eyes with a row of long hair. Labrum distinctly emarginate to 1/4 length.Antennae stout, segments 9–10 slightly wider than long. Length ratio of antennal segments: 100:50:71:58:54:38:50:42:42:50:108. Segment 3 approximately 1.4 times as long as segment 2 and 1.2 times as long as segment 4.

Prosternal process broad, very broad apically, area between coxa impressed, shiny, with few very small setose punctures, central part of rhomboidal apex slightly convex, sides impressed, surface with few setose punctures and more or less distinct longitudinal wrinkles, appears irregular.

Claws with large basal tooth.

Distribution. Somalia. The type locality Afgoi is placed in southern Somalia, Basso Scebeli Province ( fig. 28 ).

Remarks. A distinct species, close to members of the C. lacrymosa species–group but differs in very small size. With length 3.20–3.40 mm this is the smallest African member of the genus Cassida . At first glance C. nigeriana appears similar but it differs in larger size with length 4.45–4.70 mm (in C. minutissima L 3.20-3.40 mm), claws simple and elytral pattern is reddish and forms solid stripe in the posthumeral area (figs. 212, 213), while in C. minutissima the claws havea basal tooth and the pattern is reddish brown not forming a solid stripe in the posthumeral area ( figs. 210, 211 ). Both species are separated geographically, C. minutissima is known only from Somalia and C. nigeriana only from Nigeria.

Types examined. Holotype and two paratypes: [ SOMALIA]: Somalie : Afgoi / 5–X–1977 / leg. Olmi ( MNHW).

Figures

FIGURE 28. Distribution of Cassida mashonensis (black diamonds), Cassida minutissima (black square) and Cassida pernix (black circles).

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