Dicaelus Bonelli, 1813

Bousquet, Yves, 2012, Catalogue of Geadephaga (Coleoptera, Adephaga) of America, north of Mexico, ZooKeys 245, pp. 1-1722 : 628

Genus Dicaelus Bonelli, 1813

Dicaelus Bonelli, 1813: 446. Type species: Dicaelus violaceus Bonelli, 1813 (= Dicaelus purpuratus Bonelli, 1813) designated by Hope (1838: 82). Etymology. From the Greek dis (double) and coilos (hollow), alluding to the pair of impressions on the anterior part of the frons (" la tête porte sur le devant deux enfoncements très-considérables... c’est de ces deux impressions que j’ai tiré le nom Dicaelus ") of the adult [masculine].

Dicoelus Agassiz, 1846: 122, 123. Unjustified emendation of Dicaelus Bonelli, 1813.

Distribution.

Sixteen species (24 species-group taxa) restricted to the temperate and tropical zones of North America and Mexico (south to the vicinity of Mexico City). Three subgenera are recognized: Dicaelus s.str., Paradicaelus , and Liodicaelus .

Identification.

Ball (1959) revised the species of this genus. Since the publication of this work, Ball (1992a) described one new Mexican species ( Diplocheila franclemonti ), one Mexican subspecies was raised to specific level ( Diplocheila abbreviatus Bates), and another one ( Diplocheila laevipennis dicaeloides ) was placed in synonymy. A few changes are introduced here: Diplocheila subtropicus and Diplocheila quadratus treated as subspecies are raised to specific level, and Diplocheila purpuratus darlingtoni is placed in synonymy with Diplocheila quadratus .