An invaluable site for synonyms, links to original descriptions, literature, and other information. Covers the entire world, but tends to have more complete information for European and North American species. A great place to begin literature searches.
"The Lepidopterists' Society Season Summary [sometimes: LepSoc-SS] is an annual compilation of Lepidoptera records from Canada, Mexico, and the United States. Each year our members submit information regarding range extensions, host plant associations, population dynamics, etc. Automated in 1995, the database contains all records since that time plus Saturniidae and Sphingidae records since 1971."
The Field Museum just imaged 131 species that have been seen in the Chicago area and has posted them here. As of now the images can't be enlarged on the website, but we're discussing how we might be able to make the larger images available in a color rapid guide or poster format. They are also imaging their type specimens of different species groups. But again, we don't know exactly how those will become available for viewing. Will keep you posted as we learn more.
The specimens in this slideshow are representative of species that have been sighted, collected, or published in Cook County according to Butterflies and Moths of North America and The Butterflies of North America by James A.
Disclaimer: Dedicated naturalists volunteer their time and resources here to provide this service. We strive to provide accurate information, but we are mostly just amateurs attempting to make sense of a diverse natural world. If you need expert professional advice, contact your local extension office.