Chaetocnema (Chaetocnema) subbasalis 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 : 104-105

39. Chaetocnema (Chaetocnema) subbasalis Ruan, Konstantinov & Yang , New Species

( Fig. 60 )

Etymology: This species was named and designated as new by Prof. Sicien Chen (Shixiang Chen), however, he did not publish the name. We use the name originally proposed by Prof. Chen, it is a noun in apposition.

Diagnosis: This species resembles C. tonkinensis , C. nigrilata sp. nov. and C. yiei . However, it differs from all the three by the unique coloration of antennae, narrower frontal ridge and distinct shape of aedeagus. This species superficially resembles C. nigrica , due to the black dorsum. However, the body length of C. subbasalis n. sp. is conspicuously greater than that of C. nigrica and the punctation of the pronotum is quite different in these two species.

Distribution: China (Yunnan).

Host plants: Unknown.

Description: Body length: 1.85–1.95 mm. Body width: 1.10–1.15 mm. Ratio of length of antenna to length of body: 0.64–0.66. Ratio of elytron length (along suture) to width (maximum): 2.10–2.15. Ratio of pronotum width (at base) to length: 1.68–1.72. Ratio of length of elytron to length of pronotum (along middle): 2.45–2.50. Ratio of width of elytra at base (in middle of humeral calli) to width of pronotum at base: 1.10–1.12.

Dorsum black, with slight bronzy luster. Antennomeres 1–10 completely yellow brown, 11 black brown. Tarsi and tibiae yellow brown. Pro- and mesofemora deep yellow brown. Metafemora deep brown.

Head hypognathous, finely reticulated. Frontal ridge narrow, convex. Frontolateral sulcus present. Suprafrontal sulcus shallow. Orbital sulcus, supraantennal sulci deep. Ratio of width of frontal ridge (excluding margin) to width of antennal socket (excluding margin): 1.05–1.10. Number of punctures on vertex: 5–6 on each side near eye. Number of punctures on orbit: 2–3 on each side. One row of punctures present on frons below frontolateral sulcus on each side. Number of setae on clypeus: approximately 24. Number of setae on labrum: 6. Anterior margin of labrum slightly convex at middle.

Pronotum without longitudinal impressions near basal margin. Deep row of large punctures at base of pronotum present, but not prominent. Pronotal base convex. Lateral margins of pronotum slightly convex, converging forward. Anterolateral prothoracic callosity moderately developed, rounded or slightly truncate. Posterolateral prothoracic callosity poorly developed. Diameter of pronotal punctures 1–2 times smaller than distance between them.

Elytra with slightly convex lateral sides. Elytral punctures larger than those on pronotum, arranged in single rows, including peri-scutellar row. Elytral interspaces between puncture rows slightly costate. Number of rows of minute punctures on each interspace: 2–3. Humeral callus well developed.

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

Aedeagus robust and short, extremely wide in ventral view. Apex narrowing abruptly in ventral view. Ventral longitudinal groove present. Apical denticle moderately developed in ventral view. Minute transverse wrinkles on ventral side absent. Aedeagus in lateral view evenly curved, somewhat straight near apex. Maximum curvature in lateral view situated at middle.

Type: Holotype: ♂, 1) China: Yunnan, Jinghong, Ganlangju alt. 700m 21.III.1957, Chinese Academy of sciences; 2 ) Holotype; 3) Chaetocnema subbasalis sp. nov., Det. Shixiang Chen, 19; 4) Holotype, Chaetocnema subbasalis sp. nov., Des. Ruan, Konstantinov & Yang. 2017. (in the ‘type collection’ of IZCAS) .

Figures

FIGURE 60. Chaetocnema subbasalis sp. nov. A Holotype, habitus. B Pronotum and peri-scutellar area. C Head, frontal view. D Aedeagus, ventral view. E Aedeagus, lateral view. F Apex of aedeagus, ventral view. G Ventral view of Holotype