The native and introduced bark and ambrosia beetles of Michigan (Coleoptera: Curculionidae, Scolytinae)

Our knowledge of the biogeography of Scolytinae of eastern temperate North America is very patchy. We used data from hand collecting, trapped material (from 65 of 83 counties), and museum collections, supplemented by literature records, to compile a list comprising 107 bark beetle species in 45 genera for Michigan, a state with an especially rich diversity of woody plants. We provide detailed collection data documenting 32 species not previously catalogued for Michigan, 23 of which are new state records; the genera Trypophloeus and Trischidias are reported from Michigan for the first time. Fifteen Michigan scolytines are not native to North America; Ambrosiodmus rubricollis (Eichhoff), Crypturgus pusillus (Gyllenhal), Euwallacea validus (Eichhoff), Xyleborus californicus Wood, Xylosandrus crassiusculus (Motschulsky) have not previously been found in the state. We report Michigan hosts for 67 species, including 49 new host associations for the 93 native species. Despite identifying over 4000 specimens for this study, we fully expect to find many more species: over 30 additional species occur in the Great Lakes region.