Chaetocnema (Chaetocnema) fusiformis Chen & Wang, 1980

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 : 54-56

14. Chaetocnema (Chaetocnema) fusiformis Chen & Wang, 1980

( Fig. 33 )

Chaetocnema fusiformis Chen & Wang, 1980: 4 , 17. TL: China, Yunnan. TD: IZCAS.

Distribution: China (Yunnan).

Host plant: Unknown.

Description: Body elongate, obviously narrowed anteriorly and posteriorly in dorsal view. Body length 1.80– 1.90 mm, body width 1.00– 1.10 mm. Ratio of elytron length (along suture) to width (maximum): 2.30–2.40. Ratio of pronotum width (at base) to length: 1.40–1.45. Ratio of length of elytron to length of pronotum (along middle): 2.70–2.80. Ratio of width of elytra at base to width of pronotum at base (in middle of humeral calli): 1.15–1.25. Ratio of maximum width of elytra to maximum width of pronotum: 1.30–1.35.

Elytra and pronotum bronzy to golden bronzy. Antennomeres 1–3 completely yellow, 4–5 partially brown. Tibiae partially brown. Pro- and mesofemora partially brown. Metafemora dark brown.

Head hypognathous to subprognathous. Frontal ridge narrow, convex. Frontolateral sulcus present. Suprafrontal sulcus retuse, deep laterally, shallow in middle. Ratio of width of frontal ridge to width of antennal socket: 1.30–1.50. Frons with long setae laterally, glabrous in middle. Vertex flat, situated on same level as orbit. Vertex densely and evenly covered with punctures, except along midline.

Base of pronotum without short longitudinal impressions, deep row of large punctures near basal margin absent. Pronotal base strongly expanded in middle. Basal margin of pronotum covered with punctures in middle. Pronotum without shallow antebasal transverse impression. Lateral margins of pronotum slightly convex or nearly straight, converging anteriorly. Anterolateral prothoracic callosity protruding forward. Posterolateral prothoracic callosity poorly developed. Diameter of pronotal punctures larger than or subequal to distance between punctures.

Elytra with convex sides. Scutellar row of elytral punctures regular and single. Second to eleventh row of punctures regular. Humeral callus well developed. Interspaces between rows of punctures with heart shaped minute punctures.

First protarsomere in male slightly larger than second. Excavation of hind tibia moderately deep. Large lateral denticle on metatibia sharp. Metatibial serration proximal to large lateral denticle very sharp.

Aedeagus parallel-sided.Apex of aedeagus in ventral view narrowing gradually. Ventral surface of apical fourth of aedeagus with a longitudinal ridge in middle, both sides of ridge being concave. Apical denticle of aedeagus in ventral view weak, with narrowly rounded apex. Apical denticle of aedeagus in lateral view slightly curved ventrally. Minute transverse wrinkles on ventral side of aedeagus absent. Aedeagus in lateral view evenly and strongly curved.

Spermathecal pump much shorter than receptacle, with cylindrical apex. Spermathecal receptacle cylindrical. Receptacle widest near middle, basally wider than apically. Apex of vaginal palpus subtriangular, with lateral margin abruptly narrowing. Vaginal palpus parallel-sided in middle, slightly widening preapically and anteriorly. Anterior sclerotization of vaginal palpus widening anteriorly, proximal end broadly rounded. Length of posterior sclerotization greater than width. Posterior sclerotization wider than anterior.

Type: 1♀ (Holotype) ( IZCAS), 1) Mangshi , Yunnan, 900m; 2) 1955.V.17, leg. Le Wu & Buxike; 3) Chaetocnema fusiformis ; 4) holotype . 1♀ (Paratype) ( IZCAS), China: Puer , Yunnan, alt. 400m, 18.IV.1955, leg. В. Попов.

Material: 3♂ 7♀ ( IZCAS), China: Yunnan, Jinghong , alt. 550m, 1982.IV.14, leg. Subai Liao ; 19♂ 20♀ (IZ- CAS), China: Jinghong , Yunnan, 15.IV.1982, leg. Jingruo Zhou & Sumei Wang.

Remarks: This species closely resembles C. tibialis . However, C. fusciformis can be separated from C. tibialis based on structure of the aedeagus and pronotum. Aedeagus in C. fusiformis is strongly curved in lateral view compared to C. tibialis , and the posterior margin of the pronotum is expanded in the middle to form a distinct lobe in C. fusciformis .

Figures

FIGURE 33. Chaetocnema fusiformis. A Male habitus. B Pronotum. C Head, frontal view. D Aedeagus, ventral and lateral views. E Apex of aedeagus, dorsal view. F Vaginal palpi. G Spermatheca. H Tignum.