Gonioctena (Brachyphytodecta) davidi, Cho, Hee-Wook, 2017

Cho, Hee-Wook, 2017, Two new species of the subgenus Brachyphytodecta Bechyně, 1948 (Coleoptera, Chrysomelidae, Gonioctena) from Sichuan, Southwest China, Zootaxa 4272 (3), pp. 446-450 : 446-449

Gonioctena (Brachyphytodecta) davidi sp. nov.

( Figs 1–2 , 7–10 , 16 )

Type material. Holotype: male, ‘759 // MUS.HIST.NAT., A. DAVID, Moupin [= Baoxing] (Thibet), 1871 // HOLOTYPUS Gonioctena (B.) davidi sp. n. Cho & Borowiec 2014’ (MNHN).

Diagnosis. Gonioctena davidi sp. nov. is almost identical with G. kangdingensis sp. nov. in the body shape and coloration, however it can be distinguished by the thinner aedeagus without tooth-like lateral projections before apex (thicker aedeagus with a pair of tooth-like lateral projections at apical 1/ 4 in G. kangdingensis in sp. nov.). Gonioctena flavipennis (Jacoby) is also very similar ( Figs 5–6 ), but differs in the narrow and rounded apical process of aedeagus ( Fig. 15 ).

Description. Measurements in mm: length of body: 5.80; width of body: 3.80; height of body: 2.60; width of head: 1.72; interocular distance: 1.12; width of apex of pronotum: 1.90; width of base of pronotum: 3.32; length of pronotum along midline: 1.60; length of elytra along suture: 4.40.

Body oval and strongly convex ( Fig. 1 ). Head reddish-brown. Mandibles black, with dark reddish-brown band near apex. Maxillary palp black. Antennomeres 1–3 yellowish-brown, 4 darkened, 5–11 black, 11 blackish-brown apically. Pronotum reddish-brown, basal margin black. Scutellum and elytra reddish-brown. Venter reddish-brown, partially black. Legs blackish-brown to black.

Head. Vertex weakly convex, covered with sparse punctures, becoming coarser and denser toward sides. Frontal suture V-shaped, reaching anterior margin, coronal suture weak. Frons flat, strongly depressed at anterior margin, covered with dense punctures. Clypeus very narrow and trapezoidal. Anterior margin of labrum almost straight. Mandibles with 2 sharp apical teeth and a large excavation for maxillary palp on outer side. Maxillary palp 4-segmented, with apical palpomere slightly widened, truncate apically. Antennae not reaching pronotal base; antennomere 1 robust; antennomere 2 as long as 3; antennomere 3 longer than 4; antennomeres 7–10 distinctly widened, each wider than long; antennomere 11 longest, about 1.40 times as long as wide ( Fig. 7 ).

Pronotum. Lateral sides widest at base, roundly strongly narrowed anteriorly, anterior angles strongly produced ( Fig. 2 ). Anterior and lateral margins bordered, lateral margins well visible in dorsal view. Trichobothria absent on both anterior and posterior angles. Disc covered with very sparse punctures; lateral sides covered with large and moderately dense punctures; interspaces covered with fine and sparse punctures. Scutellum slightly wider than long, narrowed posteriorly.

Elytra. Lateral sides very slightly widened posteriorly, widest before middle, thence roundly narrowed posteriorly. Humeral calli well developed. Disc covered with 11 regular rows of large punctures, including a short scutellar row; interspaces covered with fine and sparse punctures. Epipleura visible except near base in lateral view. Hind wings well developed.

Venter. Hypomera weakly 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 slightly narrower than 3. Tarsal claws appendiculate.

Genitalia. Aedeagus rather thin, weakly sinuate, distinctly narrowed from apical 1/10 to rounded apex in dorsal view ( Figs 8–9 ); moderately curved with many micro-denticles on apicolateral surface in lateral view ( Fig. 10 ).

Etymology. The species is named after the French missionary and naturalist Armand David, who collected the holotype.

Distribution. China: Sichuan ( Fig. 16 ).

Figures

FIGURE 16. Distribution of Gonioctena (Brachyphytodecta) davidi sp. nov., G. (B.) kangdingensis sp. nov. and G. (B.) flavipennis.

FIGURES 1 – 6. 1 – 2. Gonioctena (Brachyphytodecta) davidi sp. nov., holotype; 3 – 4. G. (B.) kangdingensis sp. nov., holotype; 5 – 6. G. (B.) flavipennis, syntype. 1, 3, 5: dorsal habitus; 2, 4, 6: head and pronotum. Scale bars: 1.0 mm.

FIGURES 7 – 15. 7 – 10. Gonioctena (Brachyphytodecta) davidi sp. nov.; 11 – 14. G. (B.) kangdingensis sp. nov.; 15. G. (B.) flavipennis (after Cho & Borowiec 2016). 7: antenna; 8, 11, 15: aedeagus in dorsal view; 9, 12: apex of aedeagus in dorsal view; 10, 13: aedeagus in lateral view; 14: spermatheca. Scale bars: 1.0 mm (except Fig. 14: 0.5 mm).