Redescription of Five Species of Pachybrachis Chevrolat (Coleoptera: Chrysomelidae: Cryptocephalinae) of the Western USA, Including New Synonymies, Records of Greatly Expanded Ranges into the Eastern USA, and New Plant Associations

Abstract

An effort to identify a series of Pachybrachis Chevrolat, 1836 specimens from an eastern USA nature preserve led to the study of five western USA species: Pachybrachis alticola Fall, Pachybrachis conspirator Fall, Pachybrachis laevis Bowditch, Pachybrachis mercurialis Fall, and Pachybrachis nubilus Bowditch. Pachybrachis mercurialis is synonymized under P. laevis (new synonymy), and P. conspirator is synonymized under P. nubilus (new synonymy). The known range of P. laevis was extended 1,000 miles eastward. Descriptions, figures, and range maps are presented for each species.