Cassida somalica Spaeth, 1941

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 : 146-147

Cassida somalica Spaeth, 1941

( figs. 48 , 340–341 )

Cassida somalica Spaeth, 1941: 317 ; Borowiec, 1999 a: 285.

Etymology. Named after its locus typicus, Somali Region in southern Ethiopia.

Description. L: 4.40 mm, W: 3.55 mm, Lp: 1.70 mm, Wp: 2.90 mm, L/W: 1.24, Wp/Lp: 1.71. Body short–oval ( fig. 340 ).

Entire body, including head, ventrites, legs and antennae ochraceous yellow ( figs. 340, 341 ).

Pronotum elliptical, with maximum width in the middle, anterior margin regularly convex, sides narrowly rounded, no basal corners. Disc indistinctly bordered from explanate margin but with short, deep lateral impressions. Surface of disc shiny, with fine and sparse punctation. Distance between punctures several times wider than puncture diameter, interspaces regular. Explanate margin broad, impunctate, shiny, transparent with well visible honeycomb structure.

Base of elytra only slightly wider than base of pronotum, humeral angles distinctly protruding anterad, angulate. Disc convex in profile ( fig. 340 ), with distinct postscutellar and principal impressions, low H–shaped elevation, slightly elevated second interval and some elevated interspaces between rows 1 and 2 and 3 and 6. Punctation coarse arranged in completely regular rows, dense, distance between punctures mostly narrower than puncture diameter, on sides punctures almost touching each other. Marginal row distinct, its punctures as coarse as punctures in central rows. Intervals mostly as wide as or slightly narrower than rows, their surface shiny, marginal interval as wide as submarginal interval and submarginal row combined, without humeral but with flat lateral folds. Explanate margin narrow, moderately declivous, in the widest part five times narrower than disc, surface shiny with punctation and transverse grooves appears slightly irregular, transparent with well visible honeycomb structure.

Eyes very large, gena obsolete. Clypeus broad, approximately 1.3 times as wide as long. Clypeal grooves fine but well marked, converging in regular triangle, surface of clypeus flat, shiny with few very small, setose punctures. Labrum broadly emarginate to 1/5 length. Antennae stout, segments 9–10 slightly transverse. Length ratio of antennal segments: 100:57:64:64:61:50:54:46:46:50:107. Segment 3 approximately 1.1 times as long as segment 2 and approximately as long as segment 4.

Prosternum broad in the middle, strongly expanded apically, area between coxa canaliculate along sides with rows of setose punctures, central part convex, shiny, expanded apex only slightly convex in the middle, shallowly impressed laterally with several longitudinal wrinkles and small setose punctures, surface appears rugose.

Claws with small basal tooth.

Distribution. S Ethiopia ( fig. 48 ).

Remarks. A distinct species with no close relatives among African members of the genus Cassida . Its ochraceous yellow dorsal colouration without a pattern, rounded pronotal sides, elytral disc with H–shaped elevation but regularly convex in profile, coarse and dense elytral punctation arranged in completely regular rows and claws with small basal tooth are unique characters ( figs. 340, 341 ). The pale form of C. villiersi appears similar but differs in a slimmer body with L/W ratio 1.27–1.37 (in C. somalica 1.24) and in the punctate explanate margin of pronotum (fig. 207). Also a pale form of C. voiensis appears similar but differs in a more elongate and slimmer body with L/W ratio 1.32–1.42 (fig. 196).

Type examined. Holotype: [ ETHIOPIA]: Somalia mer., Bogol Magno, 14 X 1897, Vatova ( MCSNT).

Figures

FIGURE 48. Distribution of Cassida troglodytes (black circles) and Cassida somalica (black diamond).

FIGURES 340–341. Cassida somalica. 340. Dorsal; 341. Lateral.