Gonioctena (Asiphytodecta) mausonensis 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 : 169-170

Gonioctena (Asiphytodecta) mausonensis Cho & Borowiec sp. nov.

( Figs 1–2 , 25–26 )

Types. Holotype: male (BMNH), Tonkin, Montes Mauson, April, Mai 2 -3000′, H. Fruhstorfer // 24 // Jacoby Coll. 1909-28 a. // flavoplagiata Jac. // HOLOTYPUS Gonioctena (Asiphy.) mausonensis sp. n. Cho & Borowiec 2014. Paratype: 1 male (LMCM), Tonkin, Montes Mauson, April, Mai 2 -3000′, H. Fruhstorfer // PARATYPUS Gonioctena (Asiphy.) mausonensis sp. n. Cho & Borowiec 2014.

Diagnosis. Gonioctena (Asiphytodecta) mausonensis sp. nov. is very similar to G. (A.) flavoplagiata (Jacoby, 1890) in having strongly swollen last 4 antennomeres and 2 pairs of yellowish brown spots on dark elytra, which are unique characters in the subgenus Asiphytodecta . However, Gonioctena mausonensis sp. nov. can be distinguished by reddish brown venter (dark brown to black in G. flavoplagiata ) and aedeagus with subdiamondshaped apical process (straight and thin in G. flavoplagiata , Fig. 27 ).

Description. Measurements in mm (n = 2): length of body: 7.00–7.10 (mean 7.05); width of body: 5.10–5.20 (mean 5.15); height of body: 3.50–3.60 (mean 3.55); width of head: 2.17–2.22 (mean 2.20); interocular distance: 1.50–1.57 (mean 1.54); width of apex of pronotum: 2.50–2.55 (mean 2.53); width of base of pronotum: 4.30–4.52 (mean 4.41); length of pronotum along midline: 1.95–2.10 (mean 2.03); length of elytra along suture: 5.30–5.50 (mean 5.40).

Body oval and strongly convex ( Fig. 1 ). Head largely dark reddish brown. Mandibles reddish brown, apex black. Maxillary palp reddish brown. Antennomeres 1–6 yellowish brown, 6 partially darkened, 7 blackish brown, 8–11 black. Pronotum brown to blackish brown, margins black. Scutellum dark brown, basal margin black. Elytra brown to blackish brown, with 2 pairs of yellowish brown spots. Venter largely reddish brown. Legs entirely reddish brown.

Head. Vertex weakly convex, covered with sparse punctures, becoming coarser and denser toward sides. Frontal suture V-shaped, reaching anterior margin, coronal suture rather long. Frons flat, suddenly depressed at anterior margin, covered with dense punctures. Clypeus very narrow and trapezoidal. Anterior margin of labrum produced, with a blunt tooth-like projection. 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, longest; antennomere 2 shorter than 3; antennomere 3 longer than 4; antennomeres 8–10 strongly enlarged, each distinctly wider than long; antennomere 11 suboval, about 1.12 times as long as wide ( Fig. 25 ).

Pronotum. Lateral sides widest at base, roundly 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 sparse or moderately dense punctures; lateral sides covered with much larger and denser punctures; interspaces covered with fine and sparse punctures. Scutellum distinctly wider than long, narrowed posteriorly.

Elytra. Lateral sides slightly widened posteriorly, widest beyond middle, thence roundly narrowed posteriorly. Humeral calli well developed. Disc covered with irregular, coarse and large punctures except humeri, elytral suture and lateral margins; punctures partially arranged in double rows; 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 rather thin, parallel-sided, strongly narrowed in apical 1/5, setose apicolaterally, with apical process subdiamond-shaped, apex incised in dorsal view; strongly curved, with apical process strongly recurved, apex rounded in lateral view ( Fig. 26 ).

Etymology. Named after the type locality, Mau Son Mountain.

Distribution. Vietnam (Lang Son).

Figures

FIGURES 1 – 6. Dorsal habitus (1, 3, 5) and head and pronotum (2, 4, 6). 1 – 2. Gonioctena (A.) mausonensis sp. nov.; 3 – 4. G. (A.) oudai sp. nov.; 5 – 6. G. (A.) subgeminata. Scale bars: 1.0 mm.

FIGURES 25 – 32. Antenna (25, 28), aedeagus (26 – 27, 29, 31, dorsal, apical and lateral views) and spermatheca (30, 32). 25 – 26. Gonioctena (A.) mausonensis sp. nov.; 27. G. (A.) flavoplagiata; 28 – 30. G. (A.) tonkinensis stat. nov.; 31 – 32. G. (A.) subgeminata. Scale bars: 1.0 mm (except Figs 30, 32: 0.5 mm).