Tricosa Cognato, Smith & Beaver, 2020

Smith, Sarah M., Beaver, Roger A. & Cognato, Anthony I., 2020, A monograph of the Xyleborini (Coleoptera, Curculionidae, Scolytinae) of the Indochinese Peninsula (except Malaysia) and China, ZooKeys 983, pp. 1-442 : 1

Tricosa Cognato, Smith & Beaver, 2020

Tricosa Cognato, Smith & Beaver, 2020 ( Cognato et al. 2020a): 547.

Type species.

Xyleborus metacuneolus (Eggers, 1940); original designation.

Diagnosis.

2.2-3.8 mm, 2.5-3.0 × as long as wide. Tricosa is distinguished by the following combination of characters: antennal funicle 4-segmented; antennal club type 3 with one or two sutures visible on the posterior face; protibiae distinctly or obliquely triangular with six or fewer denticles on outer margin and posterior face flattened and unarmed; scutellum small, flush with elytra surface; mycangial tufts absent; elytra attenuate; elytral discal punctures seriate; and posterolateral costa absent ( Cognato et al. 2020a).

Tricosa resembles Cyclorhipidion , Cryptoxyleborus , and Fraudatrix with which it shares either a setose and/or an attenuate appearance. Tricosa is most similar to Cyclorhipidion with which it shares a setose appearance, but is distinguished by the following diagnostic characters ( Tricosa given first): protibiae obliquely triangular vs. semi-circular with evenly rounded outer edge; typically attenuate elytra vs. rounded, truncate or excavated; outer margin of protibiae with five or six socketed denticles vs. 6-9+; anterior margin of the pronotum typically serrate vs. unarmed (rarely serrate). Tricosa is distinguished from Cryptoxyleborus by the visible scutellum, and from Fraudatrix by the 4-segmented antennal funicle and antennal club type 3 with one or two sutures visible on the posterior face, and the pronotal disc being as long as or shorter than the anterior slope ( Cognato et al. 2020a).

Similar genera.

Cryptoxyleborus , Cyclorhipidion , Fraudatrix .

Distribution.

Throughout the Oriental region and New Guinea.

Gallery system.

Not described.