Prionocerus championi, Geiser, Michael, 2010

Geiser, Michael, 2010, Studies on Prionoceridae (Coleoptera: Cleroidea). II. A revision of the genus Prionocerus Perty, 1831, Zootaxa 2328, pp. 1-48 : 36-37

Prionocerus championi n. sp.

Holotype 3: "W Sumatra, Padang env., 200–500 m, S. Jakl lgt., IV. 1995 "; NHMB.

Paratypes (1 3): 1 3: same data as the holotype ( NHMB).

Type locality: Padang, Sumatra, Indonesia.

Measurements 3 (n = 2): TBL 9.9–10.7 mm, L-h 8.4–9.0 mm

HL 1.5–1.7 mm, PL 1.7–1.8 mm, EL 6.7–7.2 mm

Differential diagnosis: Very similar in coloration to P. m a l a y s i a c u s and P. opacipennis , distinguished mainly by the shape of the aedeagus and the last abdominal sternite in males, but also easily recognizable by antennal shape. Elytra and pronotum slightly more slender than in P. coeruleipennis . Body size smaller than in P. wittmeri . Easily distinguished from P. b i c o l o r, P. paiensis and P. viridiflavus by coloration.

Description: Habitus as in fig. 40 (3). Body metallic dark blue, partly with greenish lustre. Pronotum bright reddish orange. Elytra metallic dark green, in a small area at the base and around the shoulder, as well as the scutellum metallic blue. Antennae black, with the last segment reddish brown and the first three segments lighter reddish and a bluish black stripe on the dorsal surface. Maxillary and labial palpi mostly reddish brown, parts of each segment infuscate to almost black. Outer edge of labrum yellowish brown. Legs dark bluish black, claws reddish brown.

Head behind the eyes about half as wide than the middle part of the pronotum. Vertex not very shining, sparsely and very finely punctate. Frons between eyes sparsely punctate, at its narrowest part about half as broad as the length of the first antennal joint (males); in front of the eyes depressed and slightly rugose. Clypeus almost rectangular, broader than long, slightly shagreened. Labrum about as long as wide, rather flat and more coarsely punctate then the head, with wrinkly microsculpture and some longer blackish setae.

Male antennae reaching the first quarter of the elytra in length, until slightly after the humeral callus. First three segments subfiliform (basal one slightly incrassate), segments 4 and 5 slightly widened and flattened, 6– 10 of subtriangular shape, gradually more strongly widened and flattened. Last segment robust, not conspicuously widened, but clearly emarginate. First segment long, second very short, less than one third as long, third to fifth again long, although not quite as the first, sixth to tenth slightly decreasing in length, but increasing in width, the last segment longest, about one third longer than the first.

Pronotum slightly longer than broad, widest around the middle, maximal length: maximal width 1: 0.95; subhexagonal, all angles rounded, hind angles approximately 100°; all pronotal margins distinctly bordered, broadly and conspicuously around hind angles, narrowly at the front margin; basal half shallowly, obliquely impressed at both sides of the disc, part around hind angles slightly convex; shining and without any microsculpture; basal half with some yellowish, suberect pubescence, while the sparse hairs on the fore half are more blackish; the outer margin bearing few longer, black, hair-like setae.

Elytra almost exactly fitting the description of P. opacipennis above, apical half slightly less flattened, punctures slightly deeper and a bit less dense and rugose in the basal area. Scutellum like in P. coeruleipennis .

Femora slightly metallic, with fine punctures and short blackish hairs and setae. Tibiae also slightly metallic, covered with blackish setae. Tarsi not metallic, with blackish or brownish setae.

Abdomen with rather long, sparse, greyish, recumbent pubescence and some longer black, suberect setae; with rather sparse, shallow punctures and somewhat rugose texture.

Male: Last abdominal sternite larger, especially longer, than in all the preceding species, basal half of almost cylindrical shape, apical half nearly semicircular (fig. 27). Basal margin rather deeply emarginate, in the middle with almost triangular incision (although the angle is still rounded). The apical margin deeply incised, deeper than in P. coeruleipennis , the opening large and of subtriangular shape with rounded angles. The last tergite very shallowly, inconspicuously emarginate.

Aedeagus (figs. 5, 12, 19): Process of phallobase straight; the whole phallobase strongly curved and bent downwards to an angle of about 90° (in relation to the apex of the parameres). Parameres (lateral view) after the base very thick (more than double as broad as in P. coeruleipennis ), then with a very conspicuous semicircular emargination, bearing some long, brownish hairs along its edge; after the emargination again thickened, drawn into an almost spoon-shaped tip, with some minute teeth around the inner edge of the apex. Seen in dorsal view, the parameres are narrow, largely gaping, slightly curved and never parallel as in P. coeruleipennis and relatives. Median lobe rather robust, with its basal part strongly curved (about 90°), then not straight but slightly sinuate, apical part not abruptly flattened and without dorsal hook. In dorsal view with very elongate, subparallel ostium, whose hind end is not clearly delimited; after the ostium narrowed and with a long, parallel-sided tip with a very fine central furrow.

Sexual dimorphism: Unknown, there were no females available.

Variability: Unknown, the available material is too limited.

Distribution (fig. 45): So far known only from the type locality in West Sumatra, Indonesia. Probably endemic to this island.

Derivatio nominis: Named in honour of the famous British entomologist George Charles Champion (1851–1927), author of the most important and most useful work on Prionoceridae ever published ( Champion 1919).