Chaetocnema (Chaetocnema) nigrilata 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 : 84-86

29. Chaetocnema (Chaetocnema) nigrilata Ruan, Konstantinov & Yang , New Species

( Fig. 50 )

Etymology: This species is named after its nearly black color and broader body. Specific epithet is a noun in apposition.

Diagnosis: Chaetocnema nigrilata sp. nov. closely resembles C. yiei . However, C. nigrilata is much broader with dark color and aedeagus much thicker in lateral view.

Chaetocnema nigrilata sp. nov. also resembles C. longipunctata and C. kanmiyai (Palearctic Region). It differs from C. longipunctata in having fewer punctures on either side of vertex and sparsely punctate pronotum. It differs from C. kanmiyai by the elongate punctures on pronotum.

Distribution: India.

Host plants: Unkown.

Description: Body rather broad. Body length: 1.85–1.95 mm. Body width: 1.18–1.22 mm. Ratio of elytron length (along suture) to width (maximum): 1.75–1.85. Ratio of pronotum width (at base) to length: 1.70–1.75. Ratio of length of elytron to length of pronotum (along middle): 2.00–2.10. Ratio of width of elytra at base (in middle of humeral calli) to width of pronotum at base: 1.05–1.10.

Dorsum black, with bronzy sheen. Head somewhat finely reticulate. Antennomeres 1–5 completely yellow, 5–11 brown, with apical ones darkened. Apical half of tibiae brown, basal half yellow brown, tarsi dark yellow brown. Pro- and mesofemora light brown. Metafemora dark brown.

Head hypognathous. Frontal ridge narrow and convex. Frontolateral sulcus present. Suprafrontal sulcus poorly developed. Orbital sulcus shallow; supraantennal sulcus deep. Width of frontal ridge (excluding margin) to width of antennal socket (excluding margin): 2.30–2.40. Number of punctures on vertex: 5–6 on each side near eye. Number of punctures on orbit: 0–2 on each side. Number of punctures on frons (triangular area surrounded by frontolateral sulcus and clypeus): 0. Number of setae on clypeus: approximately 10. 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. Pronotal base convex, strongly expanded at middle. Lateral margins of pronotum very slightly convex, converging forward. Anterolateral prothoracic callosity not strong, somewhat truncate. Posterolateral prothoracic callosity poorly developed. Pronotal punctures longitudinal. Diameter of pronotal punctures 2–4 times smaller than distance between them.

Elytra with slightly convex lateral sides. Elytral punctures obviously larger than those of pronotum, arranged in single rows, including peri-scutellar row. Elytral interspaces between puncture rows slightly costate at sides. Humeral callus well developed.

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

In ventral view, aedeagus asymmetrical apically, apical denticle obviously slanted to right side. Apex of aedeagus in ventral view narrowing gradually. Ventral longitudinal groove poorly developed. Minute transverse wrinkles on ventral side absent. Aedeagus in lateral view only slightly curved at base and near middle, apical half straight; apical denticle bent ventrally.

Spermathecal receptacle pear-shaped. Spermathecal duct convoluted. Spermathecal pump much shorter than receptacle, with acutely narrowed apex. Vaginal palpus slightly narrowing from base till middle, thence approximately parallel sided. Anterior sclerotization of vaginal palpus slightly widening anteriorly. Posterior sclerotization longer than wide. Width of posterior sclerotization slightly less than that of anterior.

Type: Holotype: ♂, ( USNM). labels: 1) South India, Western Ghats Karnataka, Chikmagular , 7 km N. Chikmagular, 15.XI.2003, 1800m alp. meadow, 13 23 23N; 75 43 09E, leg. Konstantinov, Prathapan, Saluk; 2 ) Holotype Chaetocnema nigrilata sp. nov. Des Ruan Yongying, 2016.

Paratypes: 1♂ 3♀ ( USNM), South India, Western Ghats Karnataka, Chikmagular , 7 km N. Chikmagular, 15.XI.2003, 1800m alp. meadow, 13 23 23N; 75 43 09E, leg. Konstantinov, Prathapan, Saluk , Paratype, Chaetocnema nigrilata sp. nov. Des Ruan Yongying, 2016.

Figures

FIGURE 50. Chaetocnema nigrilata sp. nov. A Holotype habitus (Male). B Pronotum and peri-scutellar area (Holotype). C Head, frontal view (Holotype). D Aedeagus, ventral view (Paratype). E Aedeagus, lateral view (Paratype). F Apex of aedeagus, ventral view (Paratype). G Vaginal palpi (Paratype). H Spermatheca (Paratype). I Pygidium (tergite 7) of female (Paratype).