Anthracites nakanaiensis, Naskrecki, Piotr & Rentz, David C. F., 2010

Naskrecki, Piotr & Rentz, David C. F., 2010, Studies in the orthopteran fauna of Melanesia: New katydids of the tribe Agraeciini from Papua New Guinea (Orthoptera: Tettigoniidae: Conocephalinae), Zootaxa 2664, pp. 1-35 : 13-15

Anthracites nakanaiensis n. sp.

( Figs. 5 A–I)

Type locality. PAPUA NEW GUINEA: East New Britain, Nakanai Mts., Vouvou (5°26'45.5''S, 151°27'48.7''E), 866 m, 10–18.iv.2009, coll. P. Naskrecki—male holotype ( ANSP)

Differential diagnosis. This new species is similar to A. nigrifrons Karny in the overall shape of the male cercus and the titillators, but can be easily distinguished from the latter by the unique shape of the cercus ( Fig. 5 C), which possesses a sharp, subapical spine, but lacks a large, bulbous expansion on the cercus present in A. nigrifrons . In addition, the facial color pattern in these two species is different (the frons is entirely black in A. nigrifrons , striped in the new species.)

Note. The genus Anthracites currently consists of 15 species from E Africa, SE Asia, and New Guinea, which share few common characteristics, and is in a clear need of a critical taxonomic revision. The species described here is placed tentatively in the genus Anthracites based on its similarity to A. nigrifrons , but it shares little with the type species of the genus ( A. nitidus Redtenbacher ), and future studies may see it being placed in a different, most likely new genus.

General. Body cylindrical, of medium size, slender; brachypterous ( Fig. 5 A).

Head. Frons flat, oblique, largely smooth, weakly punctate only in its upper part ( Fig. 5 B); lateral carinae absent. Fastigium of frons fused with fastigium of vertex; fastigium of vertex triangular, blunt apically, at base as wide as 1/2 of antennal scapus, shorter than half of scapus. Eyes circular, weakly protruding; median ocellus reduced, indicated only by lighter spot; lateral ocelli present but strongly reduced. Antennal scapus unarmed; antennae about twice as long as body.

Thorax. Pronotum surface weakly rugose; anterior margin of pronotum straight, flat; metazona flat, posterior edge of metazona straight; lateral lobe more than twice as long as high ( Fig. 5 A); marginal fold of pronotum very narrow, smooth. Thoracic auditory spiracle narrowly oval, completely hidden under pronotum; Sternum flat; prosternum armed with two short spines; mesosternum unarmed; metasternum unarmed.

Legs. Front coxa armed with short spine, front femur armed on both margins; genicular lobes of front femur armed with single spine on both sides; front tibia unarmed dorsally, with 9 spines on posterior and 10 on anterior ventral margin, spines slightly shorter than tibia diameter; tympanum bilaterally closed, with narrow, forward facing slits. Mid femur armed on both ventral margins, but posterior margin with only 2–3 small spines at base; genicular lobes of mid femur armed with single spine on both sides; mid tibia with 8–9 spines on posterior and 11 on anterior ventral margin Hind femur armed on both ventral margins, spines on posterior margin only at base of femur, minute; genicular lobes of hind femur armed with 2 spines on each side (lower spine minute); hind tibia armed on both dorsal and ventral margins, spines on ventral margins smaller and more sparsely distributed.

Wings. Tegmen reduced, reaching posterior margin of 1st abdominal tergite, partially covered by metazona of pronotum; costal field clearly widened at base; anterior margin rounded, apical part truncate, nearly straight ( Fig. 5 G). Tegminal venation strongly reduced; veins Sc and R slightly diverging towards apex of tegmen; right stridulatory area with large, fully developed mirror; mirror roughly triangular, intersected horizontally by short vein; stridulatory file flat, weakly bent, 0.9 mm long, 0.13 mm wide, with 36 robust teeth ( Fig. 5 F). Hind wing reduced to minute, fleshy lobes. Female tegmina nearly reaching posterior margin of 1st abdominal tergite, overlapping.

Abdomen. Tenth tergite unmodified, with shallow, V-shaped incision on posterior margin. Cercus uniquely shaped, broadly triangular, with sharp basal spine internally, subapical spine, and long apical projection ( Fig. 5 C). Epiproct unmodified; small and rounded. Phallus with weakly sclerotized, paired, titillators with their dorsal surface covered with dense, minute setation ( Figs. 5 D–E). Subgenital plate broadly trapezoidal, with deep, very broad, nearly rectangular apical incision; styli cylindrical, about 3 times as long as wide. Female subgenital plate approximately rectangular, with posterior margin strongly sclerotized, broadly incised ( Fig. 5 I).

Ovipositor. Ovipositor shorter than hind femur (ratio femur/ovipositor 0.65–0.70); slightly curved; apex with both valvulae smooth, pointed ( Fig. 5 H).

Coloration. Coloration light to dark brown ( Fig. 5 A); face with dark, vertical stripes, fused at median ocellus but diverging towards outer edges of clypeus ( Fig. 5 B). Pronotum light brown dorsally, lateral lobes with diffused darker markings; hind femur with light and dark striation; abdominal terga with diffused, dark brown stripe laterally, light brown dorsally; sterna without markings.

Measurements (5 males, 5 females). body w/wings: male 24–27 (25.7±1.5), female 31–33.5 (31.7±1.1); pronotum: male 7–7.2 (7±.1), female 7–7.3 (7.1±.1); tegmen: male 3.6–4 (3.9±.2), female 3.9–4.2 (4±.1); hind femur: male 15.5–16.2 (15.9±.3), female 16–17.5 (16.6±.8); ovipositor: 11–12 (11.3±.4) mm.

Material examined (17 specimens). Papua New Guinea: East New Britain, Pomio, Nakanai Mts., Lamas, elev. 200 m (5°36'50.7''S, 151°24'28.9''E), 3–9.iv.2009, coll. P. Naskrecki— 6 females, 7 males (paratypes) ( ANSP, MCZ); Nakanai Mts., Vouvou, elev. 866 m (5°26'45.5''S, 151°27'48.7''E), 10–18.iv.2009, coll. P. Naskrecki— 2 females, 2 males (incl. holotype, 3 paratypes) ( ANSP, MCZ).

Etymology. Named after the Nakanai Mountains in New Britain, the type locality of this new species.

Figures

FIGURE 5. Anthracites nakanaiensis n. sp.: A. holotype male; B. face; C. male cerci, dorsal view; D. titillators; E. ditto, close-up of antero-lateral margin; F. stridulatory file; G. male left tegmen; H. ovipositor; I. female subgenital plate.