Ambrosia-feeding scolytids in the Xyleborina are the most abundant exotic bark beetles in North America. Many new species discoveries and taxonomic changes have occurred since their last review in 1982. The need for a worldwide revision of this tribe hampers the ability to identify species. To remedy this situation, an illustrated key is constructed and Xyleborus glabratus Eichhoff, Xyleborus similis Ferrari, and Euwallacea fornicatus (Eichhoff), which are new to North America, are reported and diagnosed. In addition the key is presented in electronic format with additional illustration ( http://scolytid.msu.edu) to increase worldwide availability and accommodate future taxonomic revision.