Tricosa Cognato, Smith and Beaver, 2020 (in Cognato et al. 2020a): 547.
2.20−3.40 mm long, 2.30−2.91 times as long as wide. Tricosa can be distinguished from all other Xyleborini genera by the following combination of characters: antennal funicle four segmented; antennal club type 3 (Hulcr et al. 2007) with one or two sutures visible on the posterior face; protibia distinctly or obliquely triangular with 6 or fewer denticles on outer margin and posterior face flattened and unarmed; scutellum small, flush with elytra surface; mycangial tufts absent; elytra attenuate; discal punctures seriate; and posterolateral costa absent.
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 and can be distinguished from by the following diagnostic characters (Tricosa given first): protibia obliquely triangular vs semi-circular with evenly rounded outer edge; typically attenuate elytra vs rounded, truncate or excavated; outer margin of protibia with 5–6 socketed denticles vs 6–9+; anterior margin of the pronotum typically serrate vs unarmed (rarely serrate). Tricosa can be distinguished from Cryptoxyleborus by the visible scutellum, and from Fraudatrix by the four segmented antennal funicle and antennal club type 3 (Hulcr et al. 2007) with one or two sutures visible on the posterior face, and the pronotal disc as long as or shorter than the anterior slope.
Cryptoxyleborus, Cyclorhipidion, and Fraudatrix
throughout the Oriental region and New Guinea