Macrolycus costus Y. Yang, Du & Liu sp. nov.

Figs 5 C, D, 6 D – F

Diagnosis.

The species resembles M. guangxiensis, but differs in the male antennae overlapping basal 2 / 3 length of elytra when inclined and a strong elytral costa III (Fig. 5 C), phallus extremely slender at basal part in ventral view (Fig. 6 D). Unlike in M. guangxiensis, the male antennae only reach elytral mid-length, elytral costa III is usually weak (Li et al. 2015: fig. 9), and phallus is relatively stout basally in ventral view (Li et al. 2015: fig. 29).

Etymology.

The specific name is derived from the Latin costa (a rib), referring to its strong elytral costae III.

Type material.

Holotype. China: ♂ (MHBU), Guangxi, Wuming, Damingshan, 1100 m, 27. v. 2011, leg. H. Y. Liu. Paratypes. 3 ♂ 4 ♀ (MHBU), same data as the holotype .

Description.

Male (Fig. 5 C). Length 12.4 mm, width at humeri 2.8 mm.

Body black. Pronotum, elytra and scutellum red. Costae of elytra orange red. Surface covered with decumbent red pubescence (Fig. 5 C).

Eyes small, interocular distance about 1.6 times greater than eye diameter. Antennae flabellate, overlapping basal 2 / 3 length of elytra when inclined. Antennomeres III – XI lamellate, lamellae pointed at apices; lamella of III 0.6 times as long as joint itself; lamella of VIII longest, 4.2 times longer than joint itself (Fig. 5 C).

Pronotum square, 1.1 times wider than long. Anterior margin widely rounded, lateral margins strongly sinuate and posterior margin bisinuate; anterior angles obtuse-angled, posterior angles sharp and moderately projected. Scutellum trapezoidal, straight at apex (Fig. 5 C).

Elytra 3.6 times longer than humeral width. Costa I as strong as II, III and IV (Fig. 5 C).

Phallus slender (Fig. 6 D – F), basal part parallel-sided in dorsal and ventral views (Fig. 6 D, E), subapical part strongly and asymmetrically inflated laterally, about twice as wide as basal part, with a fusiform ventral-cavity, apical part progressively narrowed distad, apex with a shallow V-shaped notch, about 0.46 times as wide as subapical part; basal 1 / 4 part curved ventrally in lateral view (Fig. 6 F), subapical part moderately inflated ventrally, apical part moderately expanded ventrally, and with a tapered lamella.

Female (Fig. 6 D). Similar to males, but larger in body size. Length 17.0– 18.2 mm, width at humeri 4.0– 4.5 mm. Antennae serrate and shorter, overlapping elytral mid-length when inclined. Pronotum 1.3 times wider than long, anterior angles obtuse-angled. Elytra 3.4 times longer than humeral width.

Distribution

(Fig. 2). China (Guangxi).