Cassida irrorata Weise, 1898

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 : 94-95

Cassida irrorata Weise, 1898

( figs. 24 , 72–74)

Cassida irrorata Weise, 1898: 221 ; Spaeth, 1902: 458, 1909: 268, 1912 b: 496; Borowiec, 1999 a: 259.

Cassida (Cassida) irrorata: Spaeth, 1914 b: 117, 1924: 332 .

Cassida Harnoncourti Spaeth, 1902: 458, 1924: 332 (as syn.).

Cassida (Cassida) Harnoncourti : Spaeth, 1914 b: 117.

Description. L: 7.50–9.35 mm, W: 5.60–6.90 mm, Lp: 2.80–3.30 mm, Wp: 4.55–5.20 mm, L/W: 1.34–1.46, Wp/ Lp: 1.58–1.74. Body oval, males slightly stouter than females (figs. 72, 73).

Pronotum yellow to reddish yellow, disc usually with brownish M–shaped spot, sometimes the spot reduced to a short stripe in front of scutellum and small, round spot on each side of disc. Scutellum yellow to reddish yellow. Elytral disc yellow to reddish yellow with numerous small brownish spots spread over the entire surface of disc, sometimes the pattern reduced to few spots on top of disc and few spots along each side of disc. Explanate margin yellow to reddish yellow (figs. 72–74). Head yellow to reddish yellow, prosternum from uniformly yellow to partly brown, metasternum mostly brown, abdomen usually brown each sternite no sides with yellow transverse spot and last sternite yellow apically. Antennal segments 1–6 yellow, segment 7 more or less infuscate, apical segments 8–11 brown to black.

Pronotum broadly elliptical, with maximum width in the middle, anterior margin regularly convex, sides very broadly rounded, no basal corners. Disc distinctly convex but indistinctly bordered from explanate margin, without lateral lobes, with small shallowly impressed area above head, sides of disc bordered from explanate margin by small impression. Surface of disc shiny, impunctate. Explanate margin broad, impunctate, shiny, semitransparent with more or less visible honeycomb structure.

Base of elytra not or slightly wider than base of pronotum, humeral angles moderately protruding anterad, subrounded, lateral margin of elytra behind the humeral angle not emarginate. Disc regularly convex, without hump (fig. 74), with shallow postscutellar and very shallow principal impressions, broad and low H–shaped elevation, in some specimens marked rather like impunctate H–shaped area than elevation, without other sculpture but with some impunctate oblique or transverse spaces. Punctation small, tends to form regular rows, but they are interrupted and disturbed by impunctate elytral spaces, only sutural and two submarginal rows mostly as wide as or slightly larger than puncture diameter. Marginal row distinct, its punctures as coarse as on sides of disc, with some broad elevated intervals. Intervals flat except slightly elevated second interval, in sutural part of disc four to five times wider than rows, on sides two to three times as wide as rows. Marginal row distinct, in humeral area broad, as wide as submarginal interval and two submarginal rows combined, behind the middle usually as wide as or slightly narrower than submarginal interval, no humeral folds but distinct lateral folds. Explanate margin narrow, strongly declivous, in the widest part six times narrower than disc, surface shiny, with moderately dense punctation and some short irregular grooves, appears more or less irregular, semitransparent with more or less visible honeycomb structure.

Eyes large, gena slightly shorter than last palpomere. Clypeus very broad, approximately 1.6 times as wide as long. Clypeal grooves very fine but well marked, converging in obtuse angle, clypeal plate strongly convex, its surface shiny with several very small, setose punctures, area between elevated clypeal plate and margin of eye with long hair. Labrum shallowly emarginate. Antennae moderately stout, segments 9–10 slightly longer than wide. Length ratio of antennal segments: 100:50:75:69:67:50:52:46:48:54:96. Segment 3 approximately 1.5 times as long as segment 2 and approximately 1.1 times as long as segment 4.

Prosternum narrow in the middle, moderately expanded apically, area between coxa flat with narrow longitudinal impression, shiny, without special sculpture, with very small, setose punctures, expanded apex with globular elevation in the middle, slightly impressed laterally, surface shiny, without sculpture, with very small, setose punctures.

Claws simple.

Distribution. Kenya, Rwanda, Tanzania and Zambia ( fig. 24 ).

Remarks. A member of the Cassida coagulata species–group which differ from most of the African species of the genus Cassida in large size (length always above 7 mm), strongly convex body, broadly rounded pronotal sides, elytral disc without postscutellar hump and with feebly marked elytral sculpture forming an obtuse H–shaped postscutellar mark. Only Cassida coagulata appears similar but differs in a stouter body (L/W ratio 1.24–1.36 vs. 1.34–1.46), surface of elytra more distinctly sculptured, with a higher H–shaped elevation and second interval forming elevated fold on elytral slope ( figs. 69, 70 ), antennae uniformly yellow to ochraceous (in C. irrorata apical antennal segments 8–11 brown to black), and the explanate margin of elytra always with posterolateral spots and narrow sutural spots (in C. coagulata the explanate margin of elytra is without spots).

Types examined. Lectotype and paralectotype of Cassida irrorata Weise, 1898 , designated by Borowiec, 1999: 259: [ TANZANIA]: Dar–es–Salaam, Staudinger (ZMHU); syntype of Cassida harnoncourti Spaeth, 1902 : [ TANZANIA]: Kilimandjaro (MM).

Other specimens examined. KENYA: Amboni, Valee Boisee , 1800 m, I–II 1912, 1, Alluaud & Jeannel ( MNHN) ; Bura, Wa – Taita, III 1912, 1050 m, 1, Alluaud & Jeannel ( MNHN) ; Kibwezi , 1942, 1 ( LS) , 1, Scheffer ( ZMHU) ; Narok, Loita Hills , 2050 m, 5 XI 1977, 1, Mahnert & Perret ( MNHW) .

RWANDA: Kibungo Ranch , Mpanga, 16 XII 1987, 1 ( TW) .

TANZANIA: Kilimandjaro, Bismarckhügel, Marangu, S Mawensi, II1912, 1( MNHW) ; Kilimandjaro, Kibonoto , 2, Sjöstedt ( NRS) ; Kilimandjaro Sud– Est, Moschi , 800 m, IV 1912, 9, Alluaud & Jeannel ( MNHN, MNHW) ; Pangani , 2, Methner ( ZMHU) , III 1904, 1, Methner ( MNHW) ; Same , 12–16 V 1999, 1, Buzga ( MNHW) .

ZAMBIA: Livingstone, 28 X 1941, 2, I 1942, 7, 11 I 1942, 1, 21–26 I 1942 5, 31 I 1942, 2, 7 II 1942, 2, 14 II 1942, 2, I 1943, 2, III 1943, 2, 5 XII 1943, 1, 25 XII 1943, 1, 30 XII 1943, 2, I 1944, 5, 6 II 1944, 1, W. Eichler (IZPAS).

Figures

FIGURE 24. Distribution of Cassida irregularis (black circles), Cassida irrorata (black diamonds) and Cassida luxuriosa (black squares).

FIGURES 69–71. Cassida coagulata. FIGURES 72–74. Cassida irrorata. 69–70, 72–73. Dorsal; 71, 74. Lateral.