Onychotillus Chapin, 1945

Burke, Alan & Zolnerowich, Gregory, 2017, A taxonomic revision of the subfamily Tillinae Leach sensu lato (Coleoptera, Cleridae) in the New World, ZooKeys 179, pp. 75-157 : 135-137

Onychotillus Chapin, 1945

Type species.

Onychotillus vittatus Chapin, original designation.

Distribution.

Shown in Fig. 21K.

Differential diagnosis.

Species of Onychotillus somewhat resemble small-sized members of Cymatodera and species of Cymatoderella . These genera can be differentiated without difficulty based on the number of tarsal claws. Onychotillus species have a single tarsal claw, while members of Cymatodera and Cymatoderella have two tarsal claws (Fig. 7B). Additionally, the distribution of Onychotillus does not overlap with that of Cymatodera and Cymatoderella , with the former restricted to the West Indies, while the latter two have a continental distribution.

Redescription.

Size: 3-12 mm. Color: Body ranging from light fuscous to ferrugineous; some individuals may possess one pale, median fascia on each elytron. Body: Winged species; short to moderately long, slightly robust, somewhat subparallel specimens (Fig. 5 A–B).

Head: Including eye slightly narrower than pronotum; integument coarsely punctate; punctations vary from narrow to wide; eyes large, finely faceted, feebly emarginate posteriorly, bulging laterally; antennae with 11 antennomeres, extending beyond posterior margin of pronotum; last antennomere as long as or conspicuously longer than ninth antennomere (Fig. 10 E–F); frons feebly bi-impressed; terminal labial palpi securiform; terminal maxillary palpi cylindrical, distally compressed.

Thorax: Pronotum shiny, smooth to feebly punctate; punctation may range from narrow to slightly wide; lateral margins subparallel, slightly constricted anteriorly, somewhat wider posteriorly. Prosternum: Much wider than long, smooth to rugose, variously punctate. Mesoventrite: Wider than long, smooth, feebly to moderately punctate. Metaventrite: Convex, wider than long, surface conspicuously punctate to almost smooth. Metaventral process compressed anteriorly. Metepisterna largely exposed, the elytra do not coverer these plates in lateral view.

Elytra: Short to elongate, subparallel, widest on middle half, surface moderately to coarsely punctate; punctations arranged in regular striae; punctations do not extend to apex; epipleural fold complete, narrowing toward apex.

Legs: Femora smooth to rugose; rather swollen distally; tibiae rugose to rugulose; pulvillar formula 4-4-4; one tarsal denticle, tarsal denticle subtriangular in shape.

Abdomen: Six visible ventrites. Ventrites 1-5 not impressed laterally. Sixth ventrite of males feebly differentiated from that of females; females with sixth ventrite broadly rounded, pygidium simple.

Remarks.

Onychotillus is currently composed of five species, all inhabiting the West Indies. Of the five valid species, three are thought to be restricted to Cuba ( De Zayas 1988). Based on the limited descriptive work given by De Zayas (1988), where no key for identification was provided, specimens of what appears to be Onychotillus cubana were examined (Fig. 5A); however, none of these individuals were collected in Cuba, so these specimens are tentatively assigned to O. cubana , pending further material to be examined. It is important to note that De Zayas’ descriptions were based, in most cases, on a single specimen, and access to that material has been particularly difficult. Therefore, due to the lack of availability of material and the poorly detailed descriptions given by De Zayas, three Onychotillus species are excluded from this revision, O. trinitatis , O. minuta and O. dimidiata , all endemic to Cuba. On the other hand, we examined material of Onychotillus vittatus collected in the Dominican Republic and the Cayman Islands. These collecting localities represent new distribution records for O. vittatus .

Key to species of Onychotillus