Cassida butterwecki, Borowiec, Lech, 2007

Borowiec, Lech, 2007, Two new species of Cassida Linnaeus, 1758 (Coleoptera: Chrysomelidae: Cassidinae) from Madagascar and notes on subgenera of the genus Cassida, Zootaxa 1586, pp. 47-58 : 48-51

Cassida butterwecki sp. nov.

Etymology

Dedicated to M. Butterweck, collector of the new species.

Diagnosis

A very distinct species with no close relatives in Madagascar or tropical Africa. At first glance it is more similar to the members of the African genus Fornicocassis Spaeth, 1917 than to other Cassida species. The genus Fornicocassis distinctly differs in presence of deep antennal grooves while Cassida butterwecki has venter of pronotum typical for the genus Cassida with no antennal grooves. The strongly convex elytra, the very strong elytral punctation, and the strongly declivous explanate margin of elytra characterize the following Madagascan species: Cassida frontalis Boheman, 1856 , Cassida madagascarica Borowiec, 1999 , Cassida pubescens Spaeth, 1905 , and Cassida rufomicans Fairmaire, 1904 . C. frontalis at first glance has similar shape except beeing slightly smaller in size than C. butterwecki but differs in the strong sculpture of elytra forming irregular folds and wrinkles. The pronotal sides of C. frontalis are regularly rounded and the pronotum is widest at or slightly behind the middle while in C. butterwecki pronotum is widest distinctly before the middle. The remaining three congeners form a different group of species. They are two to three times larger than C. butterwecki , with the body almost hemispherical, slope less descending than in C. butterwecki , and the pronotal sculpture forming longitudinal striation or wrinkles. They also differ in the structure of the pronotum, with broadly rounded pronotal sides, thus their pronota are regularly elliptical while in C. butterwecki the pronotum is rather subtrapezoidal.

Description

Length: 4.6–5.0 mm, width: 3.5–3.8 mm, length of pronotum: 1.7–1.9 mm, width of pronotum: 2.7–3.1 mm, length/width ratio: 1.26–1.35, width/length ratio of pronotum: 1.51–1.63. Body short-oval, strongly convex, sides and slope strongly declining (figs. 1, 2). Sexual dimorphism indistinct.

Pronotum and elytra yellowish brown, punctures of explanate margin partly marked with black, punctures in rows partly with complete or incomplete black areola, elevated intervals with few small black spots. The number of black markings vary in the type series and some specimens look predominantly pale and some predominantly spotted. Clypeus yellowish brown. Prosternal process mostly yellowish brown only elevated margins partly black. Alae of prosternum from brown to black. Central plate of metasternum yellowish brown with blackish margin. Lateral plates brown to black. Whole metasternum from dark brown to black. Abdomen in the middle dark brown and gradually paler to margins. Coxae brown to partly black, trochanters brown, femora, tibiae and tarsi yellowish. Antennal segments 1–7 yellowish, 8–11 gradually infuscate, segments 10 and 11 almost black.

Pronotum subtrapezoidal, with maximum width in anterior 1/4 length. Anterior margin softly curved, anterior corners rounded then sides distinctly converging posterad. Disc convex, distinctly divided into part above head and basal and lateral part and distinctly bordered from explanate margin by a sulcus in anterior lobes and by an impression laterally. Area above head distinctly, coarsely but shallowly punctate, distance between punctures mostly narrower than puncture diameter, interspaces flat and surface of the area appears regular. Basal and lateral part elevated, coarsely punctate, punctures almost touching each other and surface appears slightly irregular. Explanate margin with fine punctation, punctures arranged irregularly, in some parts of the margin punctures agglomerate, in other parts of margin they are in a long distance thus distances between punctures vary from as wide as to many times wider than puncture diameter. Honeycomb structure invisible. Surface of pronotum slightly dull.

Scutellum triangular, without or with very shallow transverse sulcus. Base of elytra only slightly wider than pronotum, humeri angulate, strongly protruding anterad. Disc strongly convex, sides and slope strongly declining and disc appears slightly cylindrical. In profile disc regularly convex with top of convexity in postscutellar area ( Fig. 2 ). Punctation of disc regular, very coarse, foveolate, intervals distinctly narrower than rows, linear. Interval 2 convex, forming a linear costa surrounding postscutellar impression and forming transverse wrinkle at top of disc thus H-shaped top elevation is well marked. Interval 4 also slightly convex but less convex than interval 2, at 3/4 length forms a slightly more elevated fold. Intervals 6 mostly flat but at 3/4 length also forms a short, longitudinal fold. Marginal row distinct but its punctures finer than those of disc, marginal interval well marked only below humerus, lateral transverse fold distinct, smaller transverse fold marked also below humerus and behind the middle of marginal row. Explanate margin strongly declining, moderately broad, in the widest part approximately as wide as 1/3 width of disc. Punctation of explanate margin fine and spread irregularly thus distance between punctures vary from as wide as to many times wider than puncture diameter, honeycomb structure invisible. Surface of elytra appears slightly dull. Apex of elytral epipleura with sparse, semierect to erect hair.

Eyes large, gena obsolete. Clypeus almost as wide as long, clypeal plate flat with several small punctures, surface distinctly microreticulate, slightly shiny. Clypeal grooves fine but distinct, clearly visible on whole length, run close to ventral margins of eyes and converging in regular triangle ( Fig. 4 ). Labrum emarginate to 2/5 length. Prosternal collar short, prosternal process moderately broad, in the middle slightly wider than length of trochanters, strongly expanded apically. Basal part of the prosternal process impressed along the middle, expanded apical part in the middle with round tubercle, at sides impressed and coarsely punctate.

Antennae slim, length ratio of antennal segments: 100:58:83:71:63:42:42:38:42:42:88. Segment 3 approximately 1.4 times as long as segment 2 and approximately 1.2 times as long as segment 4, segments 9 and 10 almost square. Tarsi slim, last segment extending to the apical margin of marginal setae, claws distinctly extending behind marginal setae ( Fig. 3 ). Claws simple.

Types

Holotype female: “ MADAGASKAR: Morondava, Kirindy forest, II/ III. 1990, leg. M. Butterweck” // “ HOLOTYPE des. L. Borowiec” // “ Cassida butterwecki n. sp., HOLOTYPUS, des. L. Borowiec ‘06” (preserved in Museum für Naturkunde, Stuttgart, Germany); three paratypes: “ MADAGASKAR: Morondava, Kirindy forest, II/ III. 1990, leg. M. Butterweck” // “ PARATYPE des. L. Borowiec” // “ Cassida butterwecki n. sp., PARATYPUS, des. L. Borowiec ‘06” (preserved in Museum für Naturkunde, Stuttgart, Germany; one paratype at the Department of Biodiversity and Evolutionary Taxonomy, Wrocław, Poland).

Figures

FIGURES 1 – 3. Cassida butterwecki sp. nov.: 1. Habitus dorsal; 2. Habitus lateral; 3. Tarsus.

FIGURES 4 – 5. Head: 4. Cassida butterwecki sp. nov.; 5. Cassida morondaviana sp. nov.