Files and scrapers: circumstantial evidence for stridulation in three species of Amblycerus, one new (Coleoptera: Bruchidae)

Amblycerus stridulator NEW SPECIES, A. pollens (Sharp) and A. eustrophoides (Schaeffer) have in common a fusifrom node with transverse striations on the metepisternum and an apical tooth on the metafemur. The fusiform node (file) and the apical tooth (scraper) may be stridulatory organs. Similar structures in criocerine Chrysomelidae are discussed and compared to the bruchods. Ambycerus eustrophoides and A. pollens are redescribed. Ambylcerus stridulator NEW SPECIES is described from Mexico. The species differ in the sclerites in the internal sac. patterns of pubescence, and the position of the fusiform node on the metepisternum.