Neoheteronyx tanythrix, 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 : 76-77

Neoheteronyx tanythrix sp. n.

( Figs 11–12 )

Material. Holotype ( Fig. 11 ), female, 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.

Differential diagnosis. The new species can be easily differentiated from its known congeners by the heterogeneous setosity of the elytral epipleura ( Fig. 12 ) and the partly bordered anterior margin of the pronotum.

Holotype. Female. Length 7.5 mm, greatest width 3.5 mm. Uniformly dark reddish-brown.

Antennae nine-jointed, with three-jointed club. Frontal face of clypeus deep, with dorsal margin smoothly convex and ventral margin smoothly concave; minutely punctured, with uninterrupted transverse row of large setigerous punctures bearing rather long setae. Sides of clypeus strongly convergent anteriad, with anterior margin very weakly concave in dorsal view, anterior angles broadly rounded. Clypeus coarsely and densely punctured, punctures somewhat confluent; frons and vertex more finely and sparsely punctured, punctures becoming smaller and sparser posteriad; frontoclypeal suture deep and convex; anterior part of frons weakly impressed along middle two-thirds of frontoclypeal suture; 1 rather short seta sitting on each side at end of ocular canthus and another along inner margin of eye in middle of its anterior third. Eyes large, with posterior margin weakly concave. Labrum deeply concave. Last joint of maxillary palpus elongate-fusiform, glabrous. Mentum covered with sparse long, erect setae, with patch of much denser but shorter setae at its base.

Pronotum transverse, twice as broad as long, broadest in anterior half; sides rather weakly convergent anteriad in anteriormost quarter only, smoothly convergent posteriad, slightly sinuate before posterior angles; anterior angles acute; posterior angles obtuse, shortly rounded; anterior margin bordered in lateral thirds, posterior margin mostly unbordered, except at posterior angles. Pronotum regularly and moderately-coarsely punctured, punctures as large and dense as on vertex; lateral margin of pronotum with 4 rather long, widely spaced erect setae. Scutellum glabrous, with broadly rounded tip. Elytra slightly more coarsely and densely punctured than pronotum, punctures simple, costae absent. Elytral epipleura setose along whole length, with 2 rows of setae (long in upper row, shorter in lower row) anteriorly; behind level of anterior margin of hind coxae these rows becoming one with long setae alternating with a few short setae ( Fig. 12 ). Thorax finely but conspicuously punctured. Propleura densely punctured in anterior half, some punctures setigerous with moderately long setae; more sparsely punctured in posterior half and glabrous. Prosternal process short, inclined, spine-like. Mesosternum densely punctured, punctures setigerous, their setae being short and fine; metasternum less densely punctured, glabrous except for a few short, stout setae around disc. Pygidium coarsely rugopunctate; both pygidium and sixth abdominal sternite completely covered with dense short, adpressed setae alternating with sparser long hairs. Abdominal sternites and basis of pygidium sharply and continuously carinate. Abdominal sternites coarsely, moderately densely and somewhat irregularly punctured; sternites 2–4 with 2–3 very irregular and alternating transverse rows of short curled hairs at mid-length; fifth sternite with single transverse row of somewhat longer hairs; sternites 5 and 6 abbreviated.

Protibia almost parallel-sided, strongly bidentate, with basal tooth 1.5 times as long as apical point; inner spur long and robust, attached well behind basal tooth; lower surface with medial longitudinal keel. Protibia bearing longitudinal rows of short thin setae along dorsal mid-line and inner margin, and also below basal tooth; in addition, row of stout setae present beneath apical tooth and row of rather long sparse setae present along longitudinal keel on ventral surface (anteriormost seta much longer than remaining ones). Profemora with patch of setae at base of anterior surface and complete row of short, sparse setae along ventral margin. Procoxae moderately densely pilose on inner half of anterior surface and along lateral margin. Each trochanter with row of a few short setae along ventral margin. Middle femora with 3 transverse rows of rather long, sparse setae on lower surface; hind femora with 2 widely separated transverse rows of similar but sparser setae; posterior border of middle and hind femora completely glabrous. Posterior margin of hind tibiae with 14 stout spines. Tarsal joints 1–4 narrow, with rather densely setose ventral surface. Claws symmetrical, simple, with sharp, broad lamina at base on concave side; empodium with dense patch of long setae.

Etymology. The specific epithet (from the Greek for “differently setose”) refers to the characteristic setation of the elytral epipleura; 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.