Chrysolina gyacaensis Daccordi et Yang, sp. nov.

(Figs. 3 A–E)

Diagnosis. Bronze with metallic purple; hind wing absent; pronotum with lateral callus separated by shallow punctured depression only at basal part, with dense punctures near basal lateral side; elytron with punctures forming 9 irregular single striae; inner edge of epipleura with 3 bristles; Hypomera smooth, without punctures; pygidium without longitudinal depression medially.

Description (based on holotype): Colour: Bronze with metallic purple; two basal segment of antennae reddish brown; compound eyes bronze; apex of mandible, last segment of maxillary palpi, last segment of labial palpi, apex of onychium reddish brown.

Body length: 5.52 mm, body width: 2.96 mm.

Body elongate-ovoid (Fig. 3 A), moderate large, convex in lateral view; hind wing absent.

Head: Clypeus with sparse pubescence, moderate and small punctures; frons shagreened, with dense and moderate punctures; coronal suture present, frontal suture present, but very thin, shallow; vertex with sparse and moderate punctures; compound eyes oblong, dorso-ventral eye length 0.22 mm, interocular distance 1.28 mm; distance from antennal insertion to eye: 0.19 mm; distance from antennal insertion to clypeus: 0.08 mm; mandible with two denticles, outer surface with sparse pubescence, with moderate and dense punctures; third segment of maxillary palpi shorter than fourth, apex of fourth segment of maxillary palpi truncate; antennae with basal segments narrow, widening from segments 6 to 11, antennal segment (1–11) length (in millimeter): 0.32: 0.16: 0.24: 0.24: 0.24: 0.24: 0.16: 0.16: 0.16: 0.16: 0.36 (Fig. 3 B).

Pronotum: Length: 1.60 mm; width: 2.80 mm. Sides of anterior and posterior angles without setigerous punctures; central disc with moderate and sparse punctures, similar to those of head; with lateral callus separated by shallow punctured depression only at basal part; with dense punctures near basal lateral side; lateral punctures of disc small and sparse.

Scutellum: Sub-triangular, with sparse punctures.

Elytra: Suture length: 4.16 mm; width of elytra: 3.44 mm; elytron with punctures forming 9 regular single striae, sutural stria present, punctures larger than those of side of pronotum; interspaces of elytral striae with very fine and sparse punctures, with horizontal wrinkles especially on basal part; epipleuron horizontal, with outer bor- der sharp, inner edge of epipleura with 3 sparse bristles apically.

Legs: Femora and tibiae with sparse, moderate punctures, sparse pubescence, apices of tibiae with dense pubescence; tarsomere1 of male protarsus enlarged; hind tarsi entirely pubescent beneath; relative lengths of hind tarsomeres: 5>1>3>2, tarsomere 5 not ventrally toothed (Fig. 3 E).

Venter: Hypomera smooth, without punctures; middle part of intercoxal prosternal process more than half width of apex; prosternal process with dense and moderate punctures, truncate and not emarginate behind; mesoventrite shorter than prosternum between coxae; metaventrite with dense, moderate punctures, with sparse pubescence; metaventrite shorter than prosternum; mesepisternum, mesepimeron and metepisternum without punctures; abdomen with dense, moderate punctures, sparse pubescence; last abdominal sternite of male without emargination; pygidium with arcuate apex, without longitudinal depression medially.

Median lobe of aedeagus (Figs. 3 C–D): Basal part as wide as apex; curved in lateral view. Flagellum slender.

Female unknown.

Remarks. Members of the new species are similar to those of Chrysolina mauroi Lopatin, but the punctures of pronotum are different: in the new species, the lateral callus is present only at base in, Chrysolina mauroi, the lateral callus is present on the whole length; and the aedeagus is also different.

Type material. Holotype: male, China: Xizang: Gyaca, 1981, leg. Unknown (IZAS).

Distribution. Xizang (Fig. 8).

Etymology. The new species is named for the locality of the type specimen.