Taxonomic Status of a Florida Differentiate in the Erynnis brizo Species Group: Classical Evidence (Lepidoptera: Hesperiidae: Pyrginae)

Abstract

Erynnis somnus (Lintner), a species of skipper butterfly described from peninsular Florida in 1881, was demoted to subspecies—E. brizo somnus—early in the 20th century. Erynnis brizo (Boisduval and Leconte) is in a transcontinental group of allopatric species with members that differ more from one another (especially in male genitalia) than E. brizo somnus differs from E. brizo brizo. Nevertheless, the subspecific rank of somnus is questionable. Four short but productive fieldtrips to what looked like a sizable gap between the two taxa found them geographically close, with no apparent intervening barrier, in northern Florida (where the Peninsula becomes the Panhandle) and in southeastern Georgia. Independent adult characters—size and alar ground color—covary in each taxon: somnus is smaller and darker whereas E. brizo is larger and lighter. Given these (and some subtle) differences between the taxa and their proximity, it is appropriate to consider E. somnus a species.