Chaetocnema (Udorpes) sulcicollis 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 : 191-193

82. Chaetocnema (Udorpes) sulcicollis Chen & Wang, 1980

( Fig. 111 )

Chaetocnema sulcicollis Chen & Wang, 1980: 5 , 18. TL: China, Yunnan. TD: IZCAS.

Distribution: China (Yunnan).

Host plants: Unknown.

Description: Body length: 1.75–2.10 mm, body width: 1.00– 1.30 mm. Antenna very short and robust, ratio of length of antenna to length of body: 0.44–0.46. Ratio of elytron length (along suture) to width (maximum): 2.20–2.40. Ratio of pronotum width (at base) to length: 1.30–1.40. Ratio of length of elytron to length of pronotum (along middle): 2.50–2.60. Ratio of width of elytra at base to width of pronotum at base (in middle of humeral calli): 1.10–1.15. Ratio of maximum width of elytra to maximum width of pronotum: 1.25–1.35.

Elytron and pronotum dark coppery. Antennomeres 1–3 completely yellow or partially dark brown, 4 partially brown, 5–11 completely brown. All tibiae yellow brown. All femora dark brown with metallic luster.

Head hypognathous. Frontal ridge narrow, convex. Frontolateral sulcus absent. Suprafrontal sulcus relatively deep, well recognized. Suprafrontal sulcus emarginate or obcordate. Ratio of width of frontal ridge to width of antennal socket: 2.00–2.10. Frons evenly covered with close punctures and short white setae. Vertex flat, situated at same level as orbit, densely and evenly covered with punctures.

Base of pronotum without short longitudinal impressions. Deep row of large punctures at base of pronotum absent. Pronotal base evenly convex. Pronotum with a shallow transverse depression near base. Lateral margins of pronotum strongly convex with maximum width near base. Anterolateral prothoracic callosity poorly developed. Posterolateral prothoracic callosity not prominent. Diameter of pronotal punctures: 2 to 3 times smaller than distance between adjacent punctures.

Elytra with convex lateral sides. Peri-scutellar punctures geminate and confused. Second to eleventh rows of elytral punctures regular. Humeral callus well developed. Large lateral denticle on metatibia obtuse. Metatibial serration near excavation absent.

Spermathecal pump much shorter than receptacle, apex flattened. Spermathecal receptacle sinuate. Maximum width of receptacle situated basally. Receptacle basally wider than apically. Apex of vaginal palpus evenly rounded. Anterior end of anterior sclerotization broadly rounded. Posterior sclerotization longer than wide. Posterior sclerotization wider than anterior.

Type: ♂ (Holotype) ( IZCAS), 1) China: Yunnan, Longlin alt. 1600m, 20.V.1955. leg. Xike Bu et. Le Wu. 2) Holotype. 3) Chaetocnema sulcicollis, Des. S. H. Chen.

Additional specimens: 3♀ ( IZCAS), China, Yunnan, Dali, Cangshan , alt. 1600–2300m, 2.VII.1981, leg. Shuyong Wang ; 1♂ ( IZCAS), China: Gezan, Zhongdian , Yunnan, alt. 3150m, 1981.VIII.4, leg. Shuyong Wang , near Chaetocnema bella , without hind wing, antenna shortened; 2♀ ( IZCAS), China: Gezan, Zhongdian , Yunnan, alt. 3150m, 1981.VIII.4, leg. Shuyong Wang.

Remarks: Chaetocnema sulcicollis closely resembles C. bella . However, C. sulcicollis has a weak antebasal transverse impression on pronotum which is absent in C. bella . Chaetocnema sulcicollis also resembles C. zangana in having very short antennae, and they can be separated by the shape of pronotum and aedeagus.

Body shape varies considerably in specimens of C. sulcicollis , for instance: 1) relatively smaller pronotum with reduced body size; 2) pronotum slightly narrowed, body size normal; 3) aedeagus very poorly sclerotized. In spite of such variability, all of them share several stable characters such as wings highly reduced, same coloration throughout body, characters of head capsule, stout and shortened antennae, presence of a transverse antebasal depression near base of pronotum, and the shape of aedeagus.

Figures

FIGURE 111. Chaetocnema sulcicollis. A Holotype, habitus. B Pronotum of Holotype. C Head, frontal view. D Vaginal palpi. E Spermatheca. F Pygidium (tergite 7) of female.