Chaetocnema (Chaetocnema) jinxiuensis Ruan, Konstantinov & Yang, 2019

Ruan, Yongying, Yang, Xingke, Konstantinov, Alexander S., Prathapan, Kaniyarikkal D. & Zhang, Mengna, 2019, Revision of the Oriental Chaetocnema species (Coleoptera, Chrysomelidae, Galerucinae, Alticini), Zootaxa 4699 (1), pp. 1-206 : 67-69

20. Chaetocnema (Chaetocnema) jinxiuensis Ruan, Konstantinov & Yang , New Species

( Fig. 42 )

Etymology: This species is named after the type locality. Specific epithet is a noun in apposition.

Distribution: China (Guanxi: Jinxiu).

Diagnosis: This species is very close to C. hainanensis . It can be separated from the latter by the shape of aedeagus and pronotum. It also resembles C. granulicollis , however it may be distinguished from the latter by the metallic body color and the shape of aedeagus.

Host plants: Unknown.

Description: Body length: 1.60–1.90 mm. Body width: 0.90–1.05 mm. Ratio of length of antenna to length of body: 0.55–0.65. Ratio of elytron length (along suture) to width (maximum): 2.50–2.60. Ratio of pronotum width (at base) to length: 1.60–1.65. Ratio of length of elytron to length of pronotum (along middle): 2.95–3.00. Ratio of width of elytra at base (in middle of humeral calli) to width of pronotum at base: 1.05–1.10.

Dorsum bronzy to coppery. Head and dorsum finely reticulated. Antennae entirely yellow brown. Tibiae and tarsi yellow brown, pro- and mesofemora brown. Metafemora deep brown.

Head hypognathous. Frontal ridge wide, slightly convex. Frontolateral sulcus present. Suprafrontal sulcus absent or poorly developed. Orbital sulcus deep. Frontal ridge rather wide, ratio of width of frontal ridge (excluding margin) to width of antennal socket (excluding margin): 2.60–2.70. Vertex shallowly punctate, with 17–20 punctures on each side, leaving middle longitudinal area impunctate. Orbit deeply punctate, with 2–3 punctures on each side. Number of punctures on frons (triangular area surrounded by frontolateral sulcus and clypeus): 0. Number of setae on clypeus: approximately 20. Number of setae on labrum: 6. Anterior margin of labrum straight or slightly convex at middle.

Pronotum without short longitudinal impressions near basal margin. A few deep and large punctures placed on either side near basal margin of pronotum. Pronotal base evenly convex. Lateral margins of pronotum almost straight, converging forward. Anterolateral prothoracic callosity truncate and oblique. Posterolateral prothoracic callosity poorly developed. Diameter of pronotal punctures 2 to 4 times smaller than distance between them.

Elytra with slightly convex lateral sides. Elytra slightly costate laterally on either side. Elytral punctures distinctly larger than those on pronotum. Elytral punctures arranged in single rows, including peri-scutellar row. Interspaces between striae of punctures smooth and glabrous. Number of rows of minute punctures on each interspace: 1–2. Humeral callus well developed.

First male protarsomere slightly larger than second. First male protarsomere larger than that of female. Excavation on metatibia rather deep. Large lateral denticle on metatibia obtuse. Metatibial serration proximal to large lateral denticle absent or poorly developed.

Apex of aedeagus in ventral view narrowing gradually. Ventral longitudinal groove absent. In ventral view, apical denticle narrowly rounded, merge with apex of aedeagus. Minute transverse wrinkles on ventral side absent. Aedeagus in lateral view unevenly curved, straight basally and medially, curved near apex.

Spermathecal receptacle oblong, duct short and coiled. Spermathecal pump much shorter than receptacle, apex flattened. Vaginal palpus approximately parallel-sided. Posterior sclerotization longer than wide. Width of posterior sclerotization greater than that of anterior.

Type: Holotype: ♂ ( IZCAS), labels (the first label is written in Chinese): 1) Guangxi, Jinxiu, Daping , grass slope, 10.IX.1981; 2) Chaetocnema ; 3 ) Holotype Chaetocnema jinxiuensis sp. nov. Des. Ruan et al., 2017.

Paratypes: 4♀ ( IZCAS), labels (the first label is written in Chinese): 1) Guangxi, Jinxiu, Daping , grass slope, 10.IX.1981 ; 2) Paratype; 3) Chaetocnema jinxiuensis sp. nov. Des. Ruan et al., 2017.

Figures

FIGURE 42. Chaetocnema jinxiuensis sp. nov. A Male habitus (Holotype). B Pronotum (Holotype). C Head (Holotype), frontal view. D Aedeagus, ventral view (Holotype). E Aedeagus, lateral view (Holotype). F Apex of aedeagus, ventral view (Holotype). G Vaginal palpi (Paratype). H Spermatheca (Paratype). I Pygidium (tergite 7) of female (Paratype).