A great source of information on Butterflies, Skippers, Moths, or many other insects in the U.S.A.

A collection of pointers to various kinds of information about butterflies. Entomology Links on the World Wide Web

A huge link database to insect subjects by the Colorado State Department of Entomology.

A directory and search engine of insect-related resources on the Internet compiled by Iowa State Entomology.

A great general resource on all sorts of insect related topics.

Huge collection of insect links compiled by Virginia Tech. Giant list of butterfly links to wonderful information!
The Lepidoptera Listserver