The genus Platynectes (Coleoptera: Dytiscidae: Agabinae) in Central America, with the discovery of the northernmost Neotropical species in Oaxaca, Mexico, and nomenclatural notes on the subgenus Agametrus

Abstract

Platynectes ( Agametrus ) zoque sp. nov. is described from the state of Oaxaca, Mexico. It is externally similar to the only Central American Platynectes, P. nitens (Sharp) from Panama and Costa Rica, but can be recognized by the shape of the male genitalia. The genetic distance between both species is 6.8% in the cox1 gene fragment. The finding of Platynectes in Mexico extends the known distribution of the genus in the Americas by about 1,300 km to the northwest. Thirteen species of the subgenus Agametrus Sharp are currently known, occurring in the Cordilleras from Chile to Mexico. A list of all species is provided including 10 new combinations resulting from the phylogenetic analysis of Toussaint et al. (2017): Platynectes ( Agametrus ) boliviensis (Regimbart, 1899), P. (A.) humilis (Sharp, 1882), P. (A.) labratus (Sharp, 1882), P. (A.) nitens (Sharp, 1887), P. (A.) peruvianus (Laporte, 1835), P. (A.) rotundatus (Brinck, 1948) (all from Agametrus ); P. (A.) curtulus (Regimbart, 1899), P. (A.) darlingtoni (Gueorguiev, 1971), P. (A.) gaudichaudii (Laporte, 1835), and P. (A.) muelleri (Kirsch, 1865) (all from Leuronectes Sharp). Platynectes ( Gueorguievtes ) darlingtoni Gueorguiev, 1972, a junior homonym of P. (A.) darlingtoni (Gueorguiev, 1971), is replaced with its junior subjective synonym P. multimaculatus Watts, 1978.