Tool for diagnosing ironclad and cylindrical bark beetles occurring in all 50 U.S. states and Canada

This tool is designed to aid in the identification of adult ironclad and cylindrical bark beetles, a large, worldwide group of diverse, subcortical beetles in the family Zopheridae. This group is thought to include both harmful and beneficial species. Some members (Bitoma, Colobicus, Synchita, etc.) have been associated with particular fungi known to harm or kill valuable hardwood trees, while other members (Aulonium, Colydium, Nematidium, etc.) are thought to be predaceous on the larvae and adults of other destructive, wood-boring beetle pests.

This resource includes an interactive key to genera and species, detailed fact sheets, species diagnoses, and hundreds of images to aid in the identification. Tool content was migrated in 2026 to this secure site. And taxonomy was updated following Ivie et al. (2016); two new species (Rhagodera costaefragmenta Krinksky, 2015 and Bulasconotus scaccarius Bernard & Gillett 2020) were not added.