Prionocerus wittmeri, 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 : 39-41

Prionocerus wittmeri n. sp.

Holotype 3: "K. O. Blawan, Idjen-Plateau, Java, 900–1500 Mr., 21.–24. 5. 1936, leg H. Lucht; Naturhist. Museum Basel, coll. W. Wittmer"; NHMB.

Paratypes (4 3, 10 Ƥ): 1 3, 2 Ƥ: same data as the holotype, but " 22. 5. 1936 " ( NHMB); 1 3, 4 Ƥ: "Blawan, Java, Idjen Plateau, 7. 36, Lucht; Naturhist. Museum Basel, coll. W. Wittmer" ( NHMB); 1 Ƥ: "G. Raoeng, Java, "Bajoekidoel", 450–700 Mr., 5.–21. I. 1932, leg. H. Lucht; Naturhist. Museum Basel, coll. W. Wittmer" ( NHMB); 1 3: " Indonesia, NE Java Isl., Baluran N. P., ca. 600 m, 16.–19. IV. 1996, R. Zajíček leg." ( NHMB); 1 3, 1 Ƥ: "Java, Baburan, 12.–18. 4. 1996, S. Jákl leg." ( NMPC); 2 Ƥ: "Idjen Plateau, V.-VI. 1920, H. Lucht, Blair d.t." ( DEIM).

Type locality: Ijen-Plateau, Java, Indonesia.

Measurements 3 (n = 5): TBL 11.2–13.0 mm, L-h 9.1–10.7 mm

HL 1.9–2.3 mm, PL 1.8–2.1 mm, EL 7.2–8.6 mm

Measurements Ƥ (n = 10): TBL 11.4–13.1 mm, L-h 9.4–10.9 mm

HL 1.9–2.3 mm, PL 1.7–2.1 mm, EL 7.6–8.9 mm

Differential diagnosis: Distinguished from all other species of the genus by the shape of the aedeagus and the last abdominal sternite of the male. P. coeruleipennis , which also occurs on Java, has a similar coloration, but always shorter elytra which are broader in shape. Moreover, its antennae are more strongly dilated and serrate and their last segment is always stouter in shape.

Description: Habitus as in fig. 42 (3). Body metallic green or blue. Pronotum, maxillary and labial palpi, basal and apical parts of the antennae reddish orange. Median part of the antennae (joints 4–8) slightly infuscate, brownish. Coloration of tarsi varying from black to reddish brown or reddish orange as the pronotum (especially in fore tarsi).

Head behind the eyes about half as wide as middle part of pronotum. Vertex shining but with slightly wrinkly sculpture, with some long, erect black hairs. Clypeus subrectangular, wider than long, rather flat, with some punctures and erect, brownish setae in the basal half. Labrum about as long as wide or slightly wider, rather flat and with some coarse punctures bearing erect, brownish setae.

Male antennae reaching the first quarter of the elytra in length, until slightly after the humeral callus. First three segments subfiliform, 4–10 flattened and gradually more widened. Last segment robust, large and strongly emarginate. First segment long, subcylindrical; second very short, less than one third of its length; third segment very long and narrow, longer than the first; 4–8 subequal in length, slightly shorter than the first, 8–10 decreasing in length, but increasing in width; last segment longest, very slightly longer than the third. Female antennae of similar length and shape as in male, very slightly shorter and preapical segments a little bit less flattened and widened

Pronotum about as long as broad, angles all rounded, widest in apical half, shortly before the middle, then almost evenly narrowed towards the base; distinctly bordered at the base and the basal part of the side margin, rest of the side and apical margin indistinctly bordered or not bordered; basal half shallowly, obliquely impressed between base and disc; pubescence of pronotum very sparse, yellow, decumbent. Its apical and lateral margin with some long, black, hairlike setae.

Elytra about 2.6–2.9 times as long as wide together in males, about 2.6–3.0 times in females, subparallel, widest in apical third; very densely punctate, the punctures at the base rather deep and clearly separate, rugose, confluent and shallower in the remaining area; covered with not very dense, inconspicuous pubescence consisting of very fine, rather short recumbent brownish hairs, intermixed with few long erect greyish hairs (sometimes only visible in profile); often with two or three inconspicuous, hardly visible rows of coarser granulae, but these can also be completely reduced. Margins regularly, finely and shallowly crenulate and with longer blackish setae. Scutellum about as long as wide, narrower than in P. coeruleipennis , all angles rounded, hind edge almost semicircular in shape; hind sometimes (but not always!) with deeply impressed middle furrow; regularly covered with very fine punctures (much finer than on the elytra) and some greyish recumbent pubescence.

Femora and tibiae metallic, rather densely punctured and slightly shagreened, with rather long, recumbent, brownish pubescence. Tibiae slightly metallic with brownish hairs and black setae. Tarsi not metallic, with blackish setae and some greyish, recumbent hairs.

Abdomen shining, with sparse, recumbent, greyish pubescence and some longer black, suberect setae; with very fine shallow punctures.

Male: Last abdominal sternite very large and massive, only slightly narrower and not shorter than the preceding sternite, of approximately semicircular shape with a very large arcuate emargination at its apical margin, but only very slightly emarginate basal margin (fig. 29). The apical opening is approximately triangular, as the last tergite is not emarginate, and bordered with some long, brownish hairs.

Aedeagus (figs. 7, 14, 21): entire aedeagus unusually large within the genus. Process of phallobase slightly sinuate; the whole phallobase curved and bent downwards, standing in an angle of about 80° to the parameral apex. Paramera massive and distinctly arcuate, with a slightly broadened apex, which bears a dense row of black thorns along its edge, but no dorsal tooth. Middle (preapical) part of paramera with some long brownish hairs. Seen in dorsal view, the paramera are largely gaping and slightly curved, similar to P. championi , with slightly converging apices. Median lobe robust, with its basal part strongly curved, bent downwards to an angle of about 90°, then straight and continuously narrowed until the apex in dorsal view with concave inner part, so the ostium is not very clearly delimited, but very large and with approximately parallel sides.

Sexual dimorphism: Females have the elytra slightly wider than in males, more distinctly widened in apical half, less parallel. Frons between eyes only about half as wide as between antennal insertions in males, distinctly wider in females. The last abdominal sternite shows a very remarkable sexual dimorphism (fig. 30): It has about the same size as in females of other Prionocerus species, in contrast to the extremely enlarged sternite in males, it is of approximately semicircular shape (stouter than in other Prionocerus females) and has a very deep, conspicuous incision at its basal margin, about half as long as the sternite, followed by a raised transverse ridge after its end. The whole sternite is unusually densely covered with long brownish hairs and setae.

Variability: The coloration of the elytra can vary from metallic light green to metallic deep blue. The antennal coloration can be lighter (middle part only very slightly infuscate) or darker (joints 9–10 also darkened) in some individuals. In one male specimen examined, the last antennal segment is shorter than usual, not quite reaching the third segment in length.

Distribution (fig. 45): Recorded from some localities in the highlands of eastern Java, Indonesia. Apparently endemic to this island, possibly even to Ijen and Baluran highlands.

Derivatio nominis: Named in honour of the great Swiss entomologist Dr. h. c. Walter Wittmer (1915– 1998), world specialist in Malachiidae and Cantharidae , who once had most of the type series of this species in his collection. Wittmer had accumulated a very large and interesting material of Prionoceridae during his lifetime, although he worked with them only marginally.