New host record of Dahlibruchus Bridwell, 1931 on cultivated Dahlia Cav. in Mexico and description of two new species (Coleoptera: Bruchidae)

Abstract

Dahlibruchus Bridwell is a genus in the family Bruchidae (Coleoptera: Chrysomeloidea) and all species have as host plants species in the genus Dahlia Cav. (Asteraceae). Usually they arrive on hosts when flowers appear and start feeding on nectar and pollen; later females lay eggs on bracts, and a few weeks later the adults emerge. Presently, the genus Dahlibruchus contains three species. The description of two new ones (Dahlibruchus castroi, new species and Dahlibruchus ruizi, new species) brings this number to five. A key to all species is presented. Dahlibruchus conradti Bridwell is recorded for the first time on cultivated dahlias in the country of Mexico.