Chortastus verrucosus, Jordal, 2025

Jordal, Bjarte H., 2025, Taxonomic revision of the rare Afrotropical genus Chortastus Schaufuss (Coleoptera: Scolytinae), Zootaxa 5647 (1), pp. 77-84 : 82-83

Chortastus verrucosus , sp. nov.

urn:lsid:zoobank.org:act:A0C654AC-BA37-4D05-A15D-045F469EDDC2

( Figs 23–25 )

Type material. Holotype, female: Cameroon, SW Province, Limbe , Ekonjo (900 m), ex Caloncoba sp. , 17. Nov. 2007, B. Jordal leg. [ ZMUB].

Diagnosis, female. Antennal club with two asymmetrically procurved sutures; interstriae on elytral declivity slightly raised and strongly tuberculated; female with gular tuft of setae.

Description, female. Body length 2.6 mm, 2.2 × as long as wide, colour dark brown. Frons convex, shiny, finely punctured, with short erect setae evenly distributed; underside of head (gular area) with a tuft of forward pointing setae; antenna light yellow, club with two clearly visible, asymmetrically procurved sutures, suture 1 with a partial septum. Pronotum finely punctured, shiny; vestiture of mainly short spatulate setae. Elytra with weakly impressed striae becoming more strongly impressed near and at the declivity; interstriae increasingly raised posteriorly with distinct granules on the declivity; vestiture consisting of confused short and spatulate interstrial setae. Legs of the same colour as remaining body, tarsal segment 3 distinctly lobed; all tibiae with transversely set apical denticles only, protibiae with apical corner posteriorly curved, in mesotibiae anteriorly pointed; metatibial apex with a distinct false corbel.

Etymology. A Latin nominative adjective meaning warty or rough, referring to the granulated interstriae on the posterior half of the elytra.

Remarks. This species is closely related to C. minimus but differs clearly by the raised granular interstriae on the elytral declivity, and the gular tuft of pointed setae in the female. The only other species with a gular tuft is C. orientalis which also has two visible sutures in the antennal club, albeit more strongly angulate. The two species differ further in the structure of the elytral interstriae, body size, and distribution.

A single female specimen was collected from the bark of a dead branch of Caloncoba ( Achariaceae ) in Cameroon, near Limbe. DNA sequence data are deposited in GenBank (as C. medius ) with accession numbers present for ten different gene fragments (see Pistone et al. 2018).

Figures

FIGURES 19–25. Dorsal, lateral and front view of Chortastus species. 19–21, Chortastus schenklingi female, and 22, male. 23–25, Chortastus verrucosus sp. nov., female holotype (Fig. 25, image flipped).