Chaetocnema (Chaetocnema) babai Kimoto, 1991

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 : 27-29

2. Chaetocnema (Chaetocnema) babai Kimoto, 1991

( Fig. 17 )

Chaetocnema babai Kimoto, 1991: 17 . TL: Taiwan. TD: Unknown (to the best of our knowledge, the Holotype is not present in KMNH, KUZC or TARI).

Distribution: China (Taiwan).

Host plants: Unknown.

Description: Body length: 2.20–2.40 mm. Body width: 1.30–1.35 mm. Ratio of elytron length (along suture) to width (maximum): 2.40–2.45. Ratio of pronotum width (at base) to length: 1.85–1.90. Ratio of length of elytron to length of pronotum (along middle): 2.70–2.80. Ratio of width of elytra at base (in middle of humeral calli) to width of pronotum at base: 1.10–1.15.

Body entirely black, without metallic luster. Dorsum and head smooth and shiny. Antennae with basal antennomeres yellow brown and distal ones dark brown. Tibiae with apical half darker than basal half, tarsi generally yellow brown. All femora dark brown, hind femur darker than pro- and mesofemora.

Head hypognathous. Frontal ridge moderately wide, convex. Frontolateral sulcus present. Suprafrontal sulcus deep, slightly and evenly curved. Orbital sulcus deep, straight and oblique. Ratio of width of frontal ridge (excluding margin) to width of antennal socket (excluding margin): 1.85–1.90. Number of punctures on vertex: 4–6 on each side near eye. Number of punctures on orbit: 3–5 on each side. Number of punctures on frons (triangular area surrounded by frontolateral sulcus and clypeus): 0. Number of setae on clypeus: approximately 20. Number of setae on labrum: 6. Anterior margin of labrum straight.

Pronotum without longitudinal impressions near basal margin. A deep row of large punctures present along basal margin of pronotum. Pronotal base evenly convex. Lateral margins of pronotum slightly convex, slightly converging forward. Anterolateral prothoracic callosity weak, rounded. Posterolateral prothoracic callosity poorly developed. Pronotal punctures extremely small, 3 to 5 times smaller than distance between them.

Elytra with slightly convex sides. Elytral punctures many times larger than those on pronotum, arranged in regular single rows, including peri-scutellar row. Interspaces between striae of punctures smooth, glabrous, strongly costate. Humeral callus well developed.

Excavation on metatibia moderately deep. Large lateral denticle on metatibia obtuse. Metatibial serration proximal to large lateral denticle absent or poorly developed.

Type: Paratype: 1 ( KMNH), labels: 1) Tien Chi, Alt. 2200m. Kao Hsiung Hsien, S–Taiwan, 7.VIII.1986, Col. K. Baba. 2) Chaetocnema babai Kimoto , sp. nov. Det. S. Kimoto, 1991. 3 ) Paratype.

Remarks: Chaetocnema babai is rather unique by its entirely black body, extremely minutely and weakly punctate pronotum and strongly costate interstices between elytral striae. We could not locate the Holotype, as it is not present in KMNH, KUZC or TARI.

Figures

FIGURE 17. Chaetocnema babai (photograph of paratype). A Dorsal habitus (paratype). B Head, frontal view (paratype). C Lateral view of head (paratype). D Pronotum (paratype).