A new, prairie-restricted species of Anacampsis Curtis (Lepidoptera: Gelechiidae) from Illinois .

Anacampsis wikeri (Lepidoptera: Gelechiidae), new species, is described. The larva of A. wikeri feeds on leaves of a prairie legume, leadplant, Amorpha canescens (Fabaceae). The moth is univoltine, with mature larvae occurring in late May; adults are active from early June into summer and autumn, while overwintering throughout the winter months. The adult of A. wikeri is externally very similar to that of another legume-feeding species, Anacampsis psoraliella. Sight identification of adults of these two species, especially of unreared individuals originating in the multi-state area of the Midwest in which their respective larval hostplants are sympatric, therefore is rendered problematic. Larval host plant specificity and adult genital morphology, however, allow unequivocal diagnosis. These characters are discussed, and male and female genitalia are illustrated for both species.