Gonioctena (Gonioctena) sichuana Cho & Borowiec

Cho, Hee-Wook & Borowiec, Lech, 2014, Two new species of the genus Gonioctena Chevrolat (Coleoptera, Chrysomelidae, Chrysomelinae) from Sichuan, China, Zootaxa 3765 (3), pp. 295-300 : 295-298

Gonioctena (Gonioctena) sichuana Cho & Borowiec , sp. n.

( Figs 1, 3 , 5–6 )

Type material. Holotype: male ( MNHUB), China: Sichuan, Umg. Zhangla , 3200m, 27.6.1996, D. Erber. Paratypes: 1 male ( MNHUB), same data as holotype ; 1 male ( TLMF), China: Sichuan, Paß zwischen Jiushaigou und Zhangla, 3500m, 30.6.1996, D. Erber . Additional material: 1 female ( MNHUB), same data as holotype ; 1 female ( TLMF), China: Sichuan, Tugu, 7.1992.

Diagnosis. This new species is similar to G. coreana (Bechyné) occurring in northeastern China, Korea and Russian Far East in having extremely similar colouration except some colour variation, male antenna less than half length of body, aedeagus suddenly narrowed with long apical process and its acute apex. Due to similar aedeagus with long apical process, G. arctica (Mannerheim) , G. springlovae (Bechyné) and G. gracilicornis (Kraatz) resemble these two species, but differ in long male antennae extending to 3/5 length of body. G. sichuana sp. n. can be distinguished from G. coreana by apical process of aedeagus slightly widened before apex in dorsal view (slightly narrowed before apex in G. coreana ), aedeagus slightly narrowed apically in lateral view (suddenly narrowed at apical 2/ 5 in G. coreana ( Fig. 7 )) and its generally smaller body size (5.1–6.6 mm in G. coreana ).

Description. Measurements in mm (n = 3): length of body: 4.70–5.50 (mean 5.13); width of body: 2.80–3.30 (mean 3.06); height of body: 1.90–2.30 (mean 2.10); width of head: 1.37–1.50 (mean 1.45); interocular distance: 0.90–1.00 (mean 0.97); width of apex of pronotum: 1.57–1.65 (mean 1.62); width of base of pronotum: 2.37–2.60 (mean 2.51); length of pronotum along midline: 1.20–1.30 (mean 1.27); length of elytra along suture: 3.40–4.10 (mean 3.73).

Body ( Fig. 1 ) oblong and weakly convex dorsally. Head and mouthparts black. Mandibles with narrow dark reddish brown band near apex. Antennomeres 1–5 yellowish brown, 6–7 dark brown, 8–11 black. Pronotum usually yellowish brown with a large black marking, rarely entirely black. Scutellum blackish brown. Elytra yellowish brown with 5 pairs of black spots. Venter black with hypomera and apical margin of last abdominal sternite yellowish brown. Legs black, tibiae yellowish brown except base and inner margin, tarsi dark brown to blackish brown.

Head. Vertex with sparse and small punctures. Frons rather flat, suddenly depressed anteriorly, with moderately dense and small punctures. Clypeus trapezoid with several long setae. Labrum emarginated anteriorly with several long setae. Mandibles asymmetrical; right mandible with an excavation for apical teeth of left mandible; each with 2 sharp apical teeth, a large excavation for maxillary palp at outer side. Maxillary palp 4- segmented with apical palpomere strongly widened in male; slightly widened in female. Antennae ( Fig. 5 ) reaching base of pronotum; antennomere 1 robust, longer than 3; antennomere 2 slightly longer than 3; antennomere 3 distinctly longer than 5; antennomeres 7–10 distinctly widened, each slightly longer than wide; antennomere 11 twice as long as wide.

Pronotum ( Fig. 3 ). Lateral sides widest at or near base, roundly narrowed anteriorly. Anterior margin widely emarginated. Anterior and lateral margins bordered. Lateral margins weakly visible in dorsal view. Trichobothria on posterior angles. Disc with sparse and small punctures; lateral sides with moderately dense and large punctures; denser, larger and partly confluent punctures near latero-basal margins; interspaces with sparse and fine punctures. Scutellum rounded at apex, slightly wider than long.

Elytra. Lateral sides very slightly widened posteriorly and widest at posterior 1/3, thence rounded at apex. Humeral calli well developed. Disc with 11 regular rows of large punctures, including a short scutellar row; interspaces with sparse and fine punctures. Epipleura impunctate, wholly visible in lateral view. Hind wing well developed.

Venter. Hypomera rugose with several punctures on antero-inner sides. Prosternum with moderately dense and coarse punctures bearing long setae; prosternal process weakly rugose, enlarged apically, bordered laterally, with moderately dense punctures. Metasternum with sparse and small punctures medially, moderately dense and large punctures laterally. Abdominal sternites with sparse to moderately dense punctures bearing short setae.

Legs. Moderately robust. Tibiae widened apically with a large preapical tooth. Fore legs with tarsomere 1 enlarged, very slightly narrower than 3 in male; weakly enlarged, slightly narrower than 3 in female. Tarsal claws appendiculate.

Genitalia. Aedeagus ( Fig. 6 ) parallel-sided, strongly narrowed at apical 1/3, with long apical process in dorsal view; curved, moderately narrowed apically in lateral view. Spermatheca absent.

Remarks. The only reliable diagnostic character is the shape of the aedeagus. Females were excluded from the type series.

Etymology. The specific name is derived from the type locality, Sichuan Province.

Distribution. China (Sichuan).

Figures

FIGURES 1 – 4. Dorsal habitus (1 – 2) and head and pronotum (3 – 4). 1, 3. Gonioctena sichuana sp. n.; 2, 4. Gonioctena metallica sp. n. Scale bars = 1.0 mm.

FIGURES 5 – 10. Antenna (5, 8) and aedeagus (6 – 7, 9 – 10, dorsal and lateral views). 5 – 6. Gonioctena sichuana sp. n.; 7. Gonioctena coreana; 8 – 9. Gonioctena metallica sp. n.; 10. Gonioctena yunnana. Scale bars = 1.0 mm.