Chiridopsis convexula ( Boheman, 1854 )

Świ, Jolanta, 2017, A monograph of the Afrotropical Cassidinae (Coleoptera: Chrysomelidae). Part 4. Revision of the genus Chiridopsis Spaeth, Zootaxa 4316 (1), pp. 1-85 : 27-28

Chiridopsis convexula ( Boheman, 1854)

( figs 9 , 27, 28 )

Cassida convexula Boheman, 1854: 421, 1857: 134 , 1862: 331; Gemminger and Harold, 1876: 3653.

Cassida (Cassida) convexula: Spaeth, 1914: 118 .

Chiridopsis convexula Spaeth, 1924: 350 ; Borowiec, 1999: 299.

Cassida nana Boheman, 1854: 435, 1857: 135 , 1862: 332; Gemminger and Harold, 1876: 3656; Borowiec, 1999: 299 (as syn. of Ch. convexula ).

Chirida nana: Spaeth, 1914: 127 .

Chiridopsis nana: Spaeth, 1924: 342 ; Shaw, 1956 a: 272.

Chirida Gorhami Spaeth, 1905: 112, 1914: 127 (as syn. of Ch. nana ).

Description. Le: 4.8–5.5 mm, Wi: 3.3–3.7 mm, Lp: 1.9–2.1 mm, Wp: 2.8–3.0 mm, Le/Wi: 1.36–1.51, Wp/Lp ratio: 1.43–1.50. Body elongate-oval.

Dorsum uniformly yellow ( figs 27, 28 ). Head from yellow with infuscate basal corners to mostly brown, in extreme case black. Thorax brown to black, abdomen brown to black broadly surrounded by yellow. Coxa from yellowish-brown to almost black, rest of legs yellow. Antennae yellow.

Pronotum elliptical ( fig. 27 ), with maximum width in the middle, anterior margin softly convex, sides broadly rounded, no basal corners. Surface of disc from impunctate to finely and sparsely punctate, from slightly alutaceous to shiny. Explanate margin broad, impunctate, shiny, transparent with well visible honeycomb structure.

Base of elytra moderately wider than base of pronotum ( fig. 27 ), humeral angles distinctly protruding anterad, subrounded. Disc moderately, regularly convex in profile, without impressions ( fig. 28 ). Punctation fine to moderate, on sides coarser than on top of disc, arranged in regular rows, rows 1 and 2, and 3 and 4 grouped in pairs thus intervals 1 and 3 twice narrower than intervals 2 and 4, distance between punctures from as wide as to twice times wider than puncture diameter in some populations rows shallowly impressed. Marginal row distinct, its punctures not coarser than punctures in central rows. Intervals flat, intervals 1 and 3 twice, intervals 2 and 4 three to four times wider than rows, intervals on sides of disc mostly 1.5 times wider than rows, marginal interval in humeral half twice wider than submarginal one, no humeral or lateral folds. Explanate margin narrow, strongly declivous, in the widest part 5.5 times narrower than disc, surface with shallow and sparse punctation, shiny, 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, in anterior part deep, in basal half running close to margin of eyes then converging in arch, surface of clypeus regularly convex, sometimes with shallow median groove, shiny with few very small, setose punctures. Labrum minutely emarginate to 1/5 length. Antennae slim, segments 9–10 approximately 1.6 times as long as wide. Length ratio of antennal segments: 100:58:73:73:58:50:54:58:62:62:123. Segment 3 approximately 1.3 times as long as segment 2 and as long as segment 4.

Prosternum broad in the middle, moderately expanded apically, area between coxae flat or with very shallow central impression, surface shiny, without special microsculpture, with few hairy punctures, expanded apex flat, with special sculpture, shiny, with several setose punctures.

Claws with moderate basal teeth.

Distribution. South Africa including Swaziland and Zimbabwe ( fig. 9 ).

Remarks. It belongs to the group of species with uniformly yellow dorsum. Three species of this group have clypeus mostly to completely yellow: Ch. convexula , Ch. flavipennis and Ch. parellina ( figs 27, 28 , 107, 108, 111, 112 ). Chiridopsis flavipennis distinctly differs in short-oval body, with length/width ratio approximately 1.24, and moderately declivous explanate margins while in Ch. convexula and Ch. parellina body is elongate-oval, length/ width ratio 1.29–1.48, with strongly declivous explanate margins. Chiridopsis parellina differs in elytral rows of punctures spread regularly over elytral surface, interval 2 only slightly wider than interval 1, and intervals 3 and 4 equal in width, punctures in lateral rows sparse, distance between punctures mostly twice wider than puncture dimeter while in Ch. convexula elytral rows of punctures tend to form pair (1+2, 3+4, 5+6, 7+8), interval 2 and 4 distinctly wider than intervals 1 and 3, punctures in lateral rows dense, distance between punctures mostly as wide as puncture dimeter. Chiridopsis parellina has clypeus always completely yellow while in Ch. convexula clypeus usually has infuscate basal corners or whole basal margin. Form of Ch. convexula with completely black clypeus differs from other yellow species with black clypeus in described above elytral punctation tending to foms a paired rows.

Types examined. Lectotype and 4 paralectotypes of Cassida convexula (designated by Borowiec 1999: 299): [ SOUTH AFRICA] Pt. Nat., I. Vahlb. ( NRS).

Lectotype of Cassida nana (designated by Borowiec 1999: 299): [ SOUTH AFRICA] Pt. Nat., I. Vahlb. ( NRS).

Syntype of Chirida gorhami : [ SOUTH AFRICA] Natal , Estcourt, I 1897 (MM).

Other specimens examined. SOUTH AFRICA: Machadodorp, Transvaal , X 1938, 2, Baum (1 NMP, 1 DBET) ; Oranje, Golden Gate, 14–15 I 1964, 1, A. Capener ( ZSM) ; E Transvaal, 20 km S Nelspruit , 750 m, 14 XII 1995, 1, M. Biondi (MB).

SWAZILAND: Eranchi, 5–10 I 1955, 6, A.L. Capener (4 MM, 2 LB).

ZIMBABWE: Bulawayo, Hope Fontein , 2 II 1987, 3, W. Wittmer ( NHMB, 2 LS); 28 km Bulawayo –Matopos, 3 II 1987, 2, W. Wittmer ( NHMB).

Figures

FIGURES 8 – 10. Distribution. 8. Chiridopsis melanocephala; 9. Chiridopsis convexula (black circles) and Chiridopsis klapperichi (white circle); 10. Chiridopsis rorida.

FIGURES 24 – 30. Chiridopsis aequinoctialis. 24. Male dorsal, 25. Female dorsal, 26. Female lateral; 27 – 28. Chiridopsis convexula. 27. Dorsal, 28. Lateral, 29 – 30. Chiridopsis ruandana. 29. Dorsal, 30. Lateral.

FIGURES 107 – 114. Chiridopsis parellina. 107. Dorsal, 108. Lateral, 109 – 110. Chiridopsis regionalis. 109. Dorsal, 110. Lateral; 111 – 112. Chiridopsis flavipennis. 111. Dorsal, 112. Lateral; 113 – 114. Chiridopsis zambiana. 113. Dorsal, 114. Lateral.