Gonioctena (Brachyphytodecta) arunensis Cho & Borowiec

Cho, Hee-Wook & Borowiec, Lech, 2016, On the genus Gonioctena Chevrolat (Coleoptera: Chrysomelidae: Chrysomelinae), with descriptions of seven new species from the Oriental region and Palaearctic China, Zootaxa 4067 (2), pp. 168-184 : 173-176

Gonioctena (Brachyphytodecta) arunensis Cho & Borowiec sp. nov.

( Figs 11–12 , 38–39 )

Gonioctena inconditus: Medvedev & Sprecher-Uebersachs 1998: 26 ; Kimoto 2005: 41 (misidentifications).

Type. Holotype: male ( LMCM), Num-Chichila, 15/ 1900 m 17.6. // O-Nepal Arun V.1980, C. Holzschuh // HOLOTYPUS Gonioctena (Brachy.) arunensis sp. n. Cho & Borowiec 2014.

Diagnosis. Gonioctena (Brachyphytodecta) arunensis sp. nov. is similar to G. (B.) incondita (Weise, 1898) occurring in Sikkim, India in having large body size (more than 9 mm), black head and pronotum and reddish brown elytra. However, Gonioctena arunensis sp. nov. can be distinguished by black antennae (antennomeres 1–5 generally yellowish brown in G. incondita , Fig. 13), black scutellum (reddish brown in G. incondita ), black abdomen (abdominal ventrites 2–5 reddish brown in G. incondita ), pronotum with very large punctures laterally (much smaller in G. incondita , Fig. 14) and aedeagus with apical process thin, roundly widened before apex (thick, apex widely truncate in G. incondita , Fig. 41). Gonioctena (Brachyphytodecta) lesnei (Chen, 1931) also has large body size and similar shape of aedeagus, but differs in having reddish brown head and pronotum and aedeagus with apical process thick (Fig. 42).

Description. Measurements in mm (n = 1): length of body: 9.60; width of body: 6.40; height of body: 4.30; width of head: 2.55; interocular distance: 1.75; width of apex of pronotum: 3.05; width of base of pronotum: 5.20; length of pronotum along midline: 2.40; length of elytra along suture: 7.20.

Body oval and strongly convex ( Fig. 11 ). Head black, with dark reddish brown band near apex of mandibles. Antennomeres 1–4 black, partially blackish brown, 5–11 black. Pronotum and scutellum black. Elytra reddish brown, basal margin black. Venter black, with apical margin of last abdominal ventrite reddish brown. Legs entirely black.

Head. Vertex distinctly depressed near frontal suture, covered with sparse punctures, becoming coarser and denser toward sides. Frontal suture depressed, V-shaped, coronal suture indistinct. Frons flat, strongly depressed at anterior margin, covered with dense punctures. Clypeus very narrow and trapezoidal. Anterior margin of labrum weakly concave. Mandibles with 2 sharp apical teeth, a large excavation for maxillary palp at outer side. Maxillary palp 4-segmented, with apical palpomere slightly widened, truncate apically. Antennae reaching base of pronotum; antennomere 1 robust; antennomere 2 shorter than 3; antennomere 3 longer than 4; antennomeres 7–10 widened, 7– 8 each as long as wide, 9–10 each wider than long; antennomere 11 longest, about 1.20 times as long as wide ( Fig. 38 ).

Pronotum. Lateral sides widest at base, roundly narrowed anteriorly, anterior angles strongly produced ( Fig. 12 ). Anterior and lateral margins bordered, lateral margins barely visible in dorsal view. Trichobothria absent on both anterior and posterior angles. Disc covered with very sparse punctures; lateral sides covered with very large and moderately dense punctures; interspaces covered with fine and sparse punctures. Scutellum slightly wider than long, narrowed posteriorly.

Elytra. Lateral sides subparallel, widest near middle, thence roundly narrowed posteriorly. Humeral calli well developed. Disc covered with 11 regular rows of large punctures, including a short scutellar row; punctures partially irregular, with additional punctures between striae; interspaces covered with fine and sparse punctures. Epipleura visible except near base in lateral view. Hind wing well developed.

Venter. Hypomera rugose, with a few punctures near anterolateral corners of prosternum. Prosternum covered with coarse and dense punctures bearing long setae; prosternal process enlarged apically, bordered laterally, with sparse punctures. Metasternum covered with small and sparse punctures in median region, large and dense punctures in lateral region. Abdominal ventrites covered with sparse or dense punctures bearing short setae.

Legs. Moderately robust. Tibiae widened apically, with a tooth-like projection. Fore legs with tarsomere 1 distinctly narrower than 3. Tarsal claws appendiculate.

Genitalia. Aedeagus moderately swollen laterally, with apical process roundly widened before apex in dorsal view; almost straight except base, tapering apically, with apical process recurved in lateral view ( Fig. 39 ).

Etymology. Named after the type locality, Arun Valley.

Distribution. Nepal.

Figures

FIGURES 7 – 12. Dorsal habitus (7, 9, 11) and head and pronotum (8, 10, 12). 7 – 8. Gonioctena (A.) tonkinensis stat. nov.; 9 – 10. G. (A.) sapaensis nom. nov.; 11 – 12. G. (B.) arunensis sp. nov. Scale bars: 1.0 mm.

FIGURES 33 – 39. Antenna (33, 36, 38) and aedeagus (34 – 35, 37, 39, dorsal, apical and lateral views). 33 – 34. Gonioctena (A.) oudai sp. nov.; 35. G. (A.) coccinella; 36 – 37. G. (A.) sapaensis nom. nov.; 38 – 39. G. (B.) arunensis sp. nov. Scale bars: 1.0 mm.