Cymatoderella Barr, 1962

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 : 101-103

Cymatoderella Barr, 1962

Type species.

Tillus collaris Spinola, 1844, original designation.

Distribution.

Shown in Fig. 21H.

Differential diagnosis.

Cymatoderella is most similar to various Cymatodera species of moderate dimensions. The two genera can be recognized based on the size of the ommatidia. Cymatoderella species have the diameter of the ommatidia somewhat small (Fig. 6F) compared to Cymatodera species (Fig. 12A). Additionally, the bicolored composition of the integument in Cymatoderella , with a testaceous to ferrugineous coloration on the head and pronotum and a piceous tone on the rest of the body (Fig. 3 B–D) will serve to separate these genera. Cymatodera bicolor (Say) is the only species in the genus with a similar color pattern, but it has an elongate and narrow body shape (Fig. 5E), not a robust one, as observed in Cymatoderella (Fig. 3 B–D).

Redescription.

Size: 3-7 mm. Body: Small, relatively robust individuals. Color: Pronotum bicolored, testaceous to ferruginous in the median region and piceous on the margins to uniformly testaceous to ferruginous; legs, antennae, thorax, elytra and abdominal segments piceous; head and mouthparts can be testaceous, ferruginous, or with an array of piceous tones; for C. patagoniae , visible ventrites 4-6 can be testaceous to ferruginous. Form: Small sized individuals, body short, robust, elytra subparallel to moderately expanded posteriorly.

Head: Eyes medium sized, taller than wide, bulging laterally, emarginate (Fig. 6F); sculpturing variously impressed; vestiture variable; antennal insertion located in front of emargination; clypeus emarginate medially; antennae with 11 antennomeres; sexual dimorphism slightly difficult to observe in the last abdominal segment; terminal maxillary palpi cylindrical; terminal labial palpi securiform (Fig. 3 B–D).

Thorax: Pronotum narrower than elytral base; widest at middle; sides constricted subapically; more strongly constricted behind middle; disc convex; anterior depression feebly indicated; antescutelar impression absent; posterior margin conspicuously constricted transversally. Prosternum smooth, variously punctate and vested. Mesoventrite wider than long; shiny, variously punctate. Metaventrite convex, smooth, shiny, moderately clothed.

Legs: Femora swollen; tibia slender; rugose to rugulose; tibial spur formula 2-2-2, pulvillar formula 4-4-4.

Elytra: Broad; robust; gradually expanded behind middle; humeri strongly indicated; elongate; surface convex, expanded behind middle; moderately to coarsely sculptured; sculpturing arranged in regular striae; elytral declivity somewhat steep; epipleural fold complete, narrowing toward apex; pygidium concealed in dorsal view.

Abdomen: Six visible ventrites. First visible segment shiny; smooth; 1.5 × longer than remaining segments. Ventrites 2-4 subquadrate; smooth; shiny; variously impressed and clothed; lateral margins parallel; posterior margins truncate. Fifth visible ventrite subquadrate; variously vested; lateral margins oblique; posterior margin truncate. Sixth visible ventrite subtriangular, displaying a degree of sexual dimorphism; lateral margins strongly oblique; posterior margin rounded to moderately emarginate. Fifth tergite subquadrate; posterior margin truncate. Sixth ventrite subtriangular.

Remarks.

Cymatoderella was established by Barr (1962) to separate Tillus collaris Spinola and T. patagoniae Knull, two New World species, from Tillus (Olivier), a widely distributed genus with a concentration of species in Africa and Oceania. Later on, Rifkind (1993a) described a third species, Cymatoderella morula . Cymatoderella collaris is widely distributed throughout North and Central America; the species ranges from the eastern and southern United States, extending southward to Mexico and the Central American countries of Guatemala, Honduras and El Salvador. Cymatoderella morula and C. patagoniae are species with a limited distributional range. Cymatoderella morula inhabits regions of southern Mexico, Guatemala, Honduras, and Nicaragua ( Rifkind 1993a), and C. patagoniae is found in southern Arizona and Guerrero, Michoacan and Sonora, Mexico.

Key to species of Cymatoderella Barr