Brachinus cinctellus Chaudoir, 1876

Akhil, S. V., Divya, M. & Sabu, K. Thomas, 2020, Bombardier beetles of genus Brachinus Weber, 1801 (Carabidae: Brachininae Brachinini) from India, Zootaxa 4816 (4), pp. 576-600 : 580

Brachinus cinctellus Chaudoir, 1876

Fig. 1h

Brachinus cinctellus Chaudoir, 1876: 70 ; Andrewes, 1930a: 49; Hrdlička, 2003: 215; 2017: 476

Type locality. Bangladesh: Dhaka, coll. M. S. Stevens.

Type depository. MNHN .

Specimen examined (n=1). Syntype labelled: “‘Deccan’, coll. Stevens, det. Chaudoir”.

Description. Length 6.7 mm. Head, pronotum, first two segments of antennae, palpi, scutellum, region around scutellum, sutural line, lateral line of elytra (except the base) and legs reddish yellow (with legs having a lighter shade); segments 3–4 of antennae reddish brown, rest dark brown; eyes and elytra black. Pronotum with median groove and lateral margins dark brown.

Head as long as wide, shiny, vertex smooth, frons, neck and region around eyes wrinkled, sparsely pubescent; apical segment of palpi tapering, pointed; eyes protruding; frontal foveae moderately deep; antennae short, not reaching the middle of elytra, segment 3 shorter than segment 1.

Pronotum flat, punctated, pubescent, fine wrinkles on each side of median groove; disc with apical margin sinuate, lateral region of apical margin not projecting forward, basal margin sinuate; disc laterally with anterior twothirds convex, posterior third slightly divergent, hind angles blunt, obtuse, very slightly projecting laterally; median groove shallow; lateral bead broad.

Elytra with matte surface, punctated, pubescent, base narrowed, humerus straight, corners rounded; apex without re-entrant angle; scutellum narrow, pointed; striations weak, rounded, intervals broad; both striations and intervals covered by setae; sutural line broadest at base, gradually narrowing till the middle of elytra, extending till the apex.

Distribution. BANGLADESH: Dhaka. Pakistan ( Hrdlička 2003, 2017).

Remarks. Brachinus cinctellus Chaudoir, 1876 and B. limbellus Chaudoir, 1876 are very closely related species which, according to Chaudoir (1876) are “…without any appreciable difference in the conformation of the external morphology, but different in size and colouring of the abdomen and the absence of spots on the antennae.” We consider the variation in size and colouration of the abdomen as minor variations, and spots on the antennae of B. cinctellus are not visible, which may be due to decolouration over the years.

Figures

FIGURE 1. Dorsal habitus of Indian Brachinus species: a) B. dryas Andrewes, 1936 (holotype, BMNH); b) B. inops Andrewes, 1932 (holotype, BMNH); c) B. hexagrammus Chaudoir, 1876 (syntype, MNHN); d) B. sexmaculatus Dejean, 1825 (syntype, MNHN); e) B. tetracolon Chuadoir, 1876 (syntype, MNHN); f) B. tetragrammus Chaudoir, 1876 (syntype, MNHN); g) B. pictus (Hope, 1833) (ZSIM); h) B. cinctellus Chaudoir, 1876 (syntype, MNHN); i) B. eucosmus Andrewes, 1937 (holotype, BMNH)