Aphelocerus thomasi Rifkind, 2020

Rifkind, Jacques, 2020, Aphelocerus thomasi, a new species of checkered beetle (Coleoptera: Cleridae: Clerinae) from Mexico, Insecta Mundi 2020 (831), pp. 1-3 : 1-2

Aphelocerus thomasi Rifkind , new species

( Fig. 1–2 )

Specimen examined. Holotype male: México, San Luis Potosí, Huichihuayán , VI-21-1962, J. M. Campbell ( CSCA).

Description. Length: 6.0 mm. Color: orange testaceous; head, prothorax, abdomen, black; posterior 1/3 of elytra piceous; mouthparts testaceous, antennae reddish brown; piceous elytral markings arcuately emarginate on anterior border, slightly produced anteriorly at suture ( Fig. 1 ). Head: shining, shallowly, finely punctate; surface inconspicuously set with fine, short, silvery, adpressed setae, and a few longer, more robust, black setae; antennae moderate in length; club composed of distal 4 antennomeres, gradually enlarged. Pronotum: slightly broader than long, subflattened on disk above; anterior depression distinct; surface shining, moderately densely but inconspicuously vested with fine, medium length, reclinate silvery setae, intermixed with longer, more robust suberect black setae ( Fig. 2 ). Scutellum small, densely covered with white setae. Elytra: elongate (ratio of length to width 13:7); umbones distinct; sides subparallel, arcuately, but rather gradually convergent posteriorly to separately rounded, dehiscent apices; dorsum slightly subflattened; integument shining, finely, sparsely, shallowly punctate, anterior 2/3 sparsely and inconspicuously set with short, erect pale setae, and fewer, somewhat longer and more robust erect, tawny setae; posterior margin of testaceous area with an irregular transverse band formed by a concentration of moderately long, reclinate, posteriorly oriented white setae, most conspicuous internally at suture; elytral posterior 1/3 rather densely covered with suberect and longer, erect black setae. Metasternum: shining, moderately densely clothed with medium length pale setae. Abdomen: ventrites shining, coarsely, shallowly, punctate and moderately densely clothed with fine, pale setae, ventrite 5 with hind margin broadly, feebly emarginate; ventrite 6 smaller, hind margin broadly, feebly emarginate; tergite 6 obliquely rounded laterally, subtruncate apically, somewhat excavate ventrally, surpassing ventrite 6 posteriorly.

Variation. Only the holotype is known.

Etymology. I dedicate this species to the late Michael C. Thomas, in recognition of his many contributions to the systematics of Coleoptera .

Distribution. The new species is known from San Luis Potosí, on the Atlantic versant of north central Mexico. The holotype was collected in June.

Diagnosis. Aphelocerus thomasi can be distinguished from congeners by a unique combination of color pattern and elytral shape. Most Aphelocerus species are uniformly black. Of the few bicolorous species, A. thomasi could only be confused with the similarly sized A. delicatulus (Barr) , but the latter has the head and prothorax partially testaceous, the anterior 2/3 of the elytra with a broad longitudinal dark band at the suture, and the elytral apices distinctly more rounded than the former ( Fig. 3 ). Furthermore, A. thomasi is known from a specimen collected in June on Mexico’s Atlantic side, whereas A. delicatulus has only been recorded from the Pacific versant (in the states of Sinaloa, Jalisco, Colima, Morelos, Puebla and Oaxaca), with all collections made from late August through October. The two species therefore appear to be both allopatric and phenologically isolated.

Figures

Figure 3. Aphelocerus delicatulus, habitus.

Figures 1–2. Aphelocerus thomasi, holotype. 1) Habitus. 2) Head and prothorax.