Contains descriptions, field photos, and life-size specimen photos of all Illinois¿ butterfly species. Also includes: easy-to-use quick guides depicting wing tops and undersides of Illinois butterfly species; background information and photos on butterfly life cycles, habitats, and ecology; Illinois range maps and adult flight periods, key characteristics relevant to field identification; descriptions of species that only rarely are seen in Illinois or that reside in adjacent states that could occur in Illinois. Select collection records, rare sightings, and other information that may be of interest to the butterfly enthusiast included.