Neoheteronyx calliseta, Prokofiev, 2016

Prokofiev, Artem M., 2016, On the Phytophagous Scarabs of the Subfamilies Dynastinae, Rutelinae, and Melolonthinae from the Schouten Islands (Kepulauan Biak), Indonesian Papua (Coleoptera: Scarabaeidae), Species Diversity 21, pp. 71-77 : 73-75

Neoheteronyx calliseta sp. n.

( Figs 4–6 )

Material. Holotype ( Fig. 4 ), male, Indonesia, Papua, Biak I., Biak Utar , near Napdori village , 2–3 km from right bank of Air Napdori river, black light, 10– 11.11.2012, A. M. Prokofiev leg. Paratypes: 35 males, 26 females, same locality as holotype, but 10–11 and 18– 19.11.2012.

Differential diagnosis. The new species is sharply different from its congeners in having a few very long, isolated setae on the legs, and extremely long setae on the head and the anterior and lateral pronotal margins. It is much smaller than the other known Papuan species with 8-jointed antennae (4.2–5.5 mm vs. 7.0– 7.5 mm in N. schoutensis and N. insulanus ).

Holotype. Male. Length 4.5 mm, greatest width 1.8 mm. Dark reddish-brown above, pale reddish-testaceous-brown below; legs testaceous-brown, with apices of tibiae and tarsi reddish-brown.

Antennae 8-jointed, with 3-jointed club. Frontal face of clypeus deep, with dorsal margin convex in middle, and ventral margin smoothly concave, with sparse long setae in transverse row, latter briefly interrupted in middle. Sides of clypeus strongly convergent anteriad, with anterior margin almost straight in dorsal view, anterior angles broadly rounded. Clypeus coarsely rugopunctate; frons and vertex coarsely punctured, punctures becoming smaller and spars- er posteriad; frontoclypeal suture deep, convex; anterior part of frons weakly triangularly impressed in middle; 1 long seta sitting on each side at end of ocular canthus and another along inner margin of eye at mid-length of its anterior third. Eyes large, bulging. Labrum moderately concave. Last joint of maxillary palpus elongate, with its outer edge much more convex than its inner edge. Mentum with pair of long setae centrally and with setose lateral borders.

Pronotum transverse, twice as broad as long; sides nearly parallel in posterior two-thirds but clearly convergent anteriad in anterior third; margins weakly sinuate before posterior angles; anterior angles sharply pointed; posterior angles almost straight; anterior and posterior margins unbordered. Pronotum coarsely and somewhat irregularly punctured, punctures becoming smaller at anterior and lateral borders; long setae sitting at mid-length of each half of anterior margin, at tip of anterior angle, and at end of anterior third of lateral margin; setae at anterior angles shorter than others. Scutellum irregularly double-punctured, with obtuse tip. Elytra coarsely punctured, costae indistinct. Elytral epipleura with row of well-spaced ciliate setae along whole length and with double row of very short setae below it on anterior third of epipleura only. Thorax coarsely and densely punctured, with punctures somewhat larger but sparser on metasternum; punctures of mesepimeres and metepimeres setose, with setae longer on mesepimeres; each side of metasternal disc with a few short setae posteriorly. Prosternal process well-developed, spine-like, laterally compressed. Pygidium coarsely but not very densely punctured, interspaces between punctures with shagreen-like microgranulation; posterior third and side margins of pygidium and last 2 visible abdominal sternites with dense long, erect, pale hairs. Abdominal sternites and basis of pygidium sharply continuously carinate. Abdominal sternites coarsely punctured, and some punctures setigerous; sternites 2–4 each with transverse row of suberect hairs just behind mid-length; sternites 5 and 6 abbreviated.

Protibia fusiform, with indistinct trace of basal tooth just behind apical point; inner spur long, arising much closer to mid-length than to apical point of protibia; lower surface with medial longitudinal keel. Protibia setose above and beneath with rather short, sparse setae, also bearing two long setae on lower surface anteriorly. Profemora with a few very short setae along ventral keel, and with row of dense adpressed setae medially on inner third of anterior surface. Procoxae with a few short setae apically. Each trochanter with long seta at tip (gradually increasing in length from first to last pair of legs). Middle and hind femora with 3 transverse rows of rather long sparse setae on lower surface, and with one very long seta near mid-length of posterior border. Posterior margin of hind tibia with 5+4 spines. Ventral surface of tarsal joints 1–4 multisetose; these joints considerably expanded on fore legs and weakly expanded on middle legs. Claws symmetrical, simple, with sharp broad lamina at base on concave side; empodium with cluster of numerous long setae.

Aedeagus as in Figs 5–6 . Endophallus with weakly sclerotized dorsal part bifurcate anteriorly.

Female. Length 5.0 mm, greatest width 2.2 mm. Darker than male. Protibia sharply bidentate, both teeth equidimensional. Tarsal joints 1–4 not dilated, much less setose than in male.

Variation. Length 4.2–5.0, usually 4.5 mm (males), 4.7–5.5, usually 5 mm (females); greatest width 1.5–2.0mm (males), 2.0– 2.5 mm (females). Intensity of reddish-brown color varying to some degree, but females almost always darker than males. Row of short setae sometimes extending between middle and hind legs on each side of metasternal disc. Protibia in some males almost unidentate, with very indistinct trace of basal tooth. Posterior margin of hind tibia with 4–5+4–5 spines. Other structural features very stable.

Etymology. The name is formed from Greek “kallos” (beauty) and “seta” (hair, seta), alluding to the characteristic long, isolated setae on the head, pronotum, and legs in this species; noun in apposition.

Figures

Figs 4–12. Neoheteronyx calliseta (4–6), N. schoutensis (7–10), and N. tanythrix (11–12) spp. n., holotypes: 4, 7, 11–dorsal view; 5, 9– aedeagus, lateral view; 6, 10–aedeagus, dorsal view; 8, antenna (weakly lamellate fifth joint arrowed); 12–setosity of middle third of elytral epipleura, dorsal view.Scale bars: 4, 7–9, 11=1mm; 5, 10=0.5mm; 6=0.25mm; 12=0.2mm.