AbstractThe host plants of native Ceutorhynchus Germar (Coleoptera: Curculionidae) species are poorly known in North America, and knowledge of these is essential for biological control programmes involving this genus of weevils. We hypothesised that weevil larva emergence holes on plant specimens in herbarium collections might reveal potential plant-insect associations, and help locate populations of hosts for non-target testing. We examined 1114 plant specimens in 16 genera and 60 species of Brassicaceae and found 70 specimens among 30 species that showed evidence of feeding injury and exit holes typical of Ceutorhynchus. We used this information to locate populations of two species of Ceutorhynchus. Herbarium collections may be useful tools for developing knowledge of host plant associations for species of Ceutorhynchus.