Chlamisus sexcarinatus ( Gressitt, 1942 )

Su, Liang & Zhou, Hong-Zhang, 2017, Taxonomy of the genus Chlamisus Rafinesque (Coleoptera: Chrysomelidae) from China with description of three new species, Zootaxa 4233 (1), pp. 1-138 : 100-103

Chlamisus sexcarinatus ( Gressitt, 1942)

(Figs 24-1, 24-2; 24-3; 24-4)

Gressitt, 1942b: 355 (orig.: Chlamys sexcarinata ; type locality: Taam-yuen-tung, N. Kwangtung; type deposited: LINGNAN); Gressitt, 1946: 96 (as Chlamisus sexcarinatus ; S. Kiangsi); Gressitt & Kimoto, 1961: 186 (Kwangtung).

Type material examined. CHINA: Gansu Province: 2♂♂, Wenxian, Bikou , Bi-feng-gou, 900–1450 m, 25. VI. 1998, coll. Jian Yao ; 1♂, Wenxian, Bikou , Bi-feng-gou, 900–1450 m, 25. VI. 1998, coll. Shuyong Wang ; 1♂, Wenxian, Bikou , Bi-feng-gou, 900–1450 m, 25. VI. 1998, coll. Decheng Yuan (female specimen absent).

Measurements. BL = 2.8 mm, BW = 1.8 mm, HL = 1 mm, HW = 0.9 mm, PL = 1.2 mm, PW = 1.5 mm, EL = 2.3 mm, PYL = 0.9 mm, PYW = 0.9 mm, AL = 0.65, AA = 110°.

Redescription. Body (Figs 24-1A, 24-2A) rather small and opaque. Elytra and pronotum covered with miniature-haired punctures; antennae and labrum with sparse yellow hairs, tibiae and tarsi covered with short yellowish white hairs. Body color black to dark brown; head reddish brown on vertex, yellow to reddish black on clypeus.

Head (Figs 24-1D; 24-2E) nearly round, as broad as long, finely, deeply and densely punctured, puncture intervals slightly raised; clypeus raised; labrum yellow, short and wide, triangular, three times as broad as long, eyes black.

Antennae (Figs 24-1I; 24-2C) yellowish brown, darker near apex. Scape three time as long as broad, pedicel subtriangular, 3rd and 4th slender, 5th slightly dilated, 6–10th flat and broad, serrated, 11th ovate.

Pronotum (Fig. 24-1F) deeply, densely and finely punctured, puncture intervals raised on disc; two tubercle on the lateral portion; median disc strongly and spherically elevated, median longitudinal groove of equal width throughout, not reaching posterior margin, bordered by a pair of longitudinal ridges; an oblique ridge branching from the longitudinal median ridge, and with short transverse ridges connecting them in the middle and anteriorly, which forms two ovate circle on each side, and a short ridge on each side of these structures; depressed behind anterior margin. Scutellum (Fig. 24-1H) rather long, prominent anteriorly, posterior-lateral angles acute and extended. Prosternum (Figs 24-1E; 24-2B) infundibulate, broadened in the middle, prosternal process weakly extended.

Elytra (Fig. 24-2G) slightly rounded apically, lateral sides slightly subparallel, humeri granulate; coarsely, deeply and rather sparsely punctured; suture teeth small, only absent at apex; basal margin weakly rugose from scutellum to near median row; longitudinal ridges distinct, tubercles small; sutural row consisting of three tubercles, 1st obsolete, 2nd small, 3rd merging with 3rd tubercle of median row into a transverse tubercle, 4th very small, weakly ridged between 3rd and 4th; median row longest, consisting of four tubercles, 1st situated near basal margin, 2nd merging with 2nd tubercle of humeral row into a transverse tubercle, 4th obsolete, 5th largest and longitudinal; humeral row consisting of three tubercle, 1st small and longitudinal, 3rd transverse; lateral row consisting of two tubercles, 1st small and transverse, 2nd small; one big cone-shape tubercle at the posterior-lateral angle, and a large tubercle consisting of several small tubercles above it, with a sharp tubercle next to it. Legs (Fig. 24-1J) yellowish brown, largely marked with black on sides of femora and tibiae.

Abdomen (Fig. 24-1G) densely and deeply punctured. 1st visible abdominal segment with one low tubercles near lateral margins, 5th segment with a large and shallow fovea in the middle. Pygidium (Figs 24-1C; 24-2F) as long as broad, finely and densely punctured, median longitudinal carina narrow but weak, throughout, lateral carinae obtuse, rather straight, without distinct transverse carina, all the carinae punctured, interspaces of these carinae shallowly depressed, and the lateral portions rather deeply depressed near lateral margins.

Aedeagus (Figs 24-3; 24-4) with apex of median lobe slightly narrower at one-eighth, rounded apically, with several fine hairs on top of each side, ventral side of distal part without punctures; median orifice with middle sclerite bending inwards at surface at one-sixth of median lobe, outline close to outer margin, lower part of outline slightly inclined towards the center; inner sac rounded both sides, slightly narrowed in the middle; tegmen moderately sclerotized.

Distribution. China (Gansu, Guangdong, Jiangxi, Yunnan).

Diagnosis. This species is similar to C. ruficeps in being narrowed and rounded posteriorly, the prothorax partly rugose-punctate, tubercles on the lateral portion large and obtuse, with the longitudinal groove starting at top of posterior declivity and of equal width throughout, scutellum longer and lateral carinae on pygidium much more obtuse and without distinct transverse carina.