Chaetocnema (Chaetocnema) appendiculata 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 : 25-27

1. Chaetocnema (Chaetocnema) appendiculata Ruan, Konstantinov & Yang , New Species

( Fig. 16 )

Etymology: This species is named after its disproportionately elongate antenna and legs, the name is derived from the Latin word ‘appendicula’, it is a noun in apposition.

Diagnosis: Chaetocnema appendiculata sp. nov. resembles C. yiei Kimoto. It can be differentiated from C. yiei and other Oriental Chaetocnema species by the disproportionately robust and long antennae and legs; hind tibia with extremely deep excavation and strongly produced tooth; and elytra rather short compared to pronotum and head.

Distribution: India.

Host plants: Unknown.

Description: Body length: 1.80–1.85 mm. Body width: 1.00– 1.05 mm. Ratio of length of antenna to length of body: 0.74–0.75. Ratio of elytron length (along suture) to width (maximum): 2.25–2.30. Ratio of pronotum width (at base) to length: 1.50–1.75. Ratio of length of elytron to length of pronotum (along middle): 2.10–2.15. Ratio of width of elytra at base (in middle of humeral calli) to width of pronotum at base: 1.03–1.05.

Dorsum dark brown, with extremely slight bronzy luster. Head and pronotum finely reticulated. Antennomeres 1–5 completely yellow brown, 6–11 brown, not dark. Pro- and meso- tarsi and tibiae yellow brown. Pro- and mesofemora generally brown, with apex yellow brown. Metatarsi and tibiae red brown. Metafemora deep red brown.

Head hypognathous. Frontal ridge narrow and convex. Frontolateral sulcus present. Suprafrontal sulcus poorly developed, shallow, gently curved upwards. Orbital, supra-antennal sulci moderately developed. Ratio of width of frontal ridge (excluding margin) to width of antennal socket (excluding margin): 1.80–1.90. Number of punctures on vertex: 7–10 on each side near eye. Punctures absent on orbit and frons (triangular area surrounded by frontolateral sulcus and clypeus). Number of setae on clypeus: approximately 10-12. Number of setae on labrum: 6. Anterior margin of labrum straight.

Pronotum without longitudinal impressions near basal margin. Deep, conspicuous row of large punctures at base of pronotum present. Pronotal base convex. Lateral margins of pronotum slightly and evenly convex, not obviously converging forward. Anterolateral prothoracic callosity weak, merge with lateral margin. Posterolateral prothoracic callosity poorly developed. Pronotal punctures extremely shallow and tiny, longitudinal. Diameter of pronotal punctures 2–4 times smaller than distance between adjacent punctures.

Elytra with slightly convex sides. Elytral punctures many times larger than those on pronotum. Punctures on elytron arranged in regular single rows, including peri-scutellar row. Elytral interspaces between puncture rows slightly costate at middle, strongly costate at sides. Elytral humeral callus moderately developed.

First male protarsomere larger than second. Excavation on metatibia extremely deep. Large lateral denticle on metatibia produced and sharp. Metatibial serration proximal to large lateral denticle absent.

Aedeagus in ventral view narrowing gradually towards apex. Ventral longitudinal groove absent. Apical denticle in ventral view absent. Minute transverse wrinkles on ventral side absent. Aedeagus in lateral view unevenly curved, somewhat sinusoidal near apex. Maximum curvature in lateral view situated at middle.

Type: Holotype: ♂ ( BMNH), labels: India, Shembaganur Madura, Inde, Collection J. Achard; 2 ) Holotype Chaetocnema appendiculata sp. nov. Des. Ruan et al., 2016.

Figures

FIGURE 16. Chaetocnema appendiculata sp. nov. A Holotype, dorsal view. B Pronotum and peri-scutellar area. C Head, frontal view. D Aedeagus, ventral view. E Aedeagus, lateral view. F Apex of aedeagus, ventral view.