Chaetocnema (Chaetocnema) salixis Ruan, Konstantinov & Yang, 2014

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 : 97-98

36. Chaetocnema (Chaetocnema) salixis Ruan, Konstantinov & Yang, 2014

( Fig. 57 )

Chaetocnema (Chaetocnema) salixis Ruan, Konstantinov & Yang, 2014: 64 . TL: China, Shannxi; TD: IZCAS.

Host plants: Salix sp. ( Salicaceae ) (Ruan et al., 2014).

Distribution: China (Shannxi, Gansu, Sichuan).

Description: Body length: 2.10–2.45 mm. Body width: 1.13–1.17 mm. Ratio of length of antenna to length of body: 0.60. Ratio of elytron length (along suture) to width (maximum): 2.70–2.75. Ratio of pronotum width (at base) to length: 1.74–1.79. Ratio of length of elytron to length of pronotum (along middle): 3.47–3.49. Ratio of width of elytra at base (in middle of humeral calli) to width of pronotum at base: 1.16–1.19. Ratio of maximum width of elytra to maximum width of pronotum: 1.44–1.47.

Elytra and pronotum not concolorous: elytra entirely black, without metallic luster, pronotum and head bronzy. Antennomere 1 partially dark brown, 2–3 partially brown or completely yellow, 4 brown, 5–11 black to dark brown. Tibiae and tarsi partially brown. Femora brown.

Head hypognathous. Frontal ridge narrow and convex. Frontolateral sulcus present. Suprafrontal sulcus deep laterally, absent in middle. Orbital sulcus deep. Width of frontal ridge (excluding margin) to width of antennal socket (excluding margin): 1.20–1.25. Ratio of width of frontolateral sulcus to width of antennal socket: 0.29–0.38. Ratio of width of orbital sulcus to width of frontolateral sulcus: 0.72. Number of punctures on vertex near each eye: 7–9. Number of punctures on orbit: 2. Number of setae along frontolateral sulcus: 9–11. Number of punctures on frons (triangular area surrounded by frontolateral sulcus and clypeus): 0. Number of setae on clypeus: 8. Number of setae on labrum: 6. Anterior margin of labrum slightly concave in middle.

Pronotum with two obscure longitudinal impressions visible only near basal margin. Deep row of large punctures at base of pronotum present laterally, absent in middle. Pronotal base slightly expanded in middle. Lateral margins of pronotum slightly convex, converging forward. Anterolateral prothoracic callosity protruding laterally, forming sharp angle laterally. Posterolateral prothoracic callosity poorly developed. Diameter of pronotal punctures 2 to 4 times smaller than distance between them.

Elytra with convex sides. All rows of punctures regular. Humeral callus well developed. Interspaces between striae of punctures smooth and glabrous. Number of striae of minute punctures on each interspace: 2.

First male protarsomere slightly wider than second. First male protarsomere, length to width ratio: 1.74–1.78. First and second male protarsomeres, length to length ratio: 1.60–1.80. First and second male protarsomeres, width to width ratio: 1.04–1.20. First male protarsomere, width at apex to width at base ratio: 1.50–1.53. Length of metatibia to distance between denticle and metatibial apex: 2.28–2.36. Large lateral denticle on metatibia sharp. Metatibial serration proximal to large lateral denticle absent or obscure. First male metatarsomere, length to width ratio: 2.80–3.40. First and second male metatarsomeres, length to length ratio: 2.03–2.15. First and second male metatarsomeres, width to width ratio: 0.87–0.97. Third and fourth male metatarsomeres, length to length ratio: 0.52–0.55.

Apex of aedeagus in ventral view narrowing gradually with polygonal marks on sides. Ventral longitudinal groove absent. Apical denticle absent in ventral view. Minute transverse wrinkles on ventral side absent. Aedeagus in lateral view evenly and strongly curved, slightly sinusoidal near apex. Maximum curvature of aedeagus in lateral view situated medially.

Spermathecal receptacle oblong. Basal part of spermathecal duct straight. Spermathecal pump much shorter than receptacle, narrowed towards apex. Receptacle basally as wide as apically. Posterior sclerotization of tignum spoon-shaped, wider than mid-section. Mid-section of tignum nearly straight. Anterior sclerotization of tignum about as wide as mid-section. Apex of vaginal palpus subtriangular, with slightly convex lateral margin. Vaginal palpus narrowing from base till middle, thence slightly widening towards apex. Anterior sclerotization of vaginal palpus nearly parallel sided. Anterior end of anterior sclerotization broadly rounded. Posterior sclerotization longer than wide. Anterior sclerotization wider than posterior.

Types: ♂ (Holotype) ( IZCAS), 1) Yangxian, Qinling Mountains, Shannxi , alt. 1700m, VII.2013, leg. Yongying Ruan, host: salix sp. 2) Holotype, Chaetocnema salixis sp. nov., Des. Ruan, Konstantinov, Yang. 2014; 2♂ 4♀ (Para- types), Qinling Mountain , Shannxi, VII–VIII.2013, leg. Yongying Ruan, host: Salix sp.; 3♂ 4♀ (Paratypes), same la- bel except leg. A. Konstantinov ( USNM); 1♂ 2♀ (Paratypes), Shatang forestry station, Zhouqu , Gansu, alt. 2400m, 5–27.VII.1998, leg. Shuyong Wang et al.; 1♀ (Paratype), Bifenggou , Bikou , Wenxian , Gansu, 25.VII.1998, alt. 2360m, leg. Xingke Yang; 1♀ (Paratype), Daheba , Tanchang , Gansu, 5.VII.1998, alt. 1700–2350m, leg. Shuyong Wang; 4♀ (Paratypes), Miyaluo , Lixian , Sichuan, alt. 2780–3300m, 7.VII.1963, leg. Xuezhong Zhang; 19♂ 48♀ (Paratypes), Sanshenggou , Wolong , Sichuan, alt. 2500–2700m, 6–8.VIII.1983, leg. Shuyong Wang. All paratypes are in IZCAS, except those indicated as deposited in USNM.

Remarks: Chaetocnema salixis resembles the Palearctic species C. transbaicalica . It may be distinguished from the latter by the following characters of C. salixis : anterolateral callosity of pronotum long and sharp laterally ( Fig. 57 B 2 ); both longitudinal groove and transverse wrinkles on ventral surface of aedeagus absent; metatibial serration proximal to large lateral denticle absent or obscure.

Figures

FIGURE 2. Chaetocnema constricta on host plant Rubus simplex (Rosaceae). Photography information: Ruan, Fujian Province, China, 13.VI. 2017.

FIGURE 57. Chaetocnema salixis. A Holotype, habitus. B1 Prothorax, dorsal view; B2 anterolateral callosity of pronotum. C Head, frontal view. D Aedeagus, ventral and lateral views. E Apex of aedeagus, dorsal view. F Vaginal palpi. G Spermatheca. H Tignum.