Two species of crane flies, Tipula oleracea L. and T. paludosa Meigen, native to the Palearctic, are well established, important pests damaging turfgrass and pastures in the Pacific Northwest and Canadian Maritimes. Both species have been recently documented in parts of the northeast U.S. and central Canada (Ontario, Quebec, New York, Michigan) and will continue to spread as new pests of lawns at homes, businesses and golf courses throughout eastern North America. Adult overall appearance and phenology of these two pest species is similar to some non-target native species of crane flies that can be found in similar habitats. We have developed an interactive, online identification guide which will be an important tool for use by agricultural extension agents, pest control operators and home owners to distinguish pest from non-pest species and avoid unnecessary application of insecticides. This project involved developing taxonomic characters for 22 crane fly species likely to be found in turfgrass or pastures, distinguishing the adult and larval stages of these pest and non-pest species, and developing these characters into an on-line interactive identification aid (key) using 20q software developed by Discover Life project (http://www.discoverlife.org/20/q ). Characters were illustrated by line drawings or photographs taken by the Automontage microscope digital imaging system.