Skippers: bay skipper (Euphyes bayensis)
(Lepidoptera: Hesperiidae: Hesperiinae)
Profile prepared by Mace Vaughan and Matthew Shepherd, The Xerces Society for Invertebrate Conservation
The bay skipper lives only in tidal sawgrass marshes in Mississippi and Texas. Little is known about this recently discovered species. Although it is likely to be found at other sawgrass marshes along the Gulf coast, the lack of records from adjacent states suggests that it does have a limited range, and there is no doubt that this species is very rare. Because of its rarity and its use of coastal salt marsh habitat, over collection, natural disasters, and mosquito spraying are all potential threats.
Xerces Red List Status: Vulnerable Other Rankings: Canada – Species at Risk Act: N/A Canada – provincial status: N/A Mexico: N/A USA – Endangered Species Act: None USA – state status: None NatureServe: G1G3 IUCN Red List: N/A
Although the distribution is uncertain, there is no doubt that this species is very rare. Any species with such a restricted range and small number of populations is vulnerable to extirpation.
The Bay Skipper is a small butterfly in the family Hesperiidae. Its wingspan is 37 to 44 mm (1½ to 1¾ inches). The upperside of the males is black with a large orange patch on each wing. The forewing has a prominent black stigma. The females are dark brown with yellow spots on the forewing and a yellow streak on the hindwing. The underside is brown (paler than the female upperside) with pale yellow spots on the forewing and two obvious yellow streaks running from the base to the margin. The bay skipper is very similar to the dion skipper (Euphyes dion), but the upperside of the wings is brighter orange and the black borders are narrower.
Euphyes bayensis Shuey, 1989. Also known as the bay St. Louis skipper. Scientists still need to review the entire E. dion complex, but the taxon of E. bayensis is mostly recognized. However, some scientists remain skeptical. E. bayensis and E. dion are sympatric, but occupy different habitats, at least in Mississippi.
The bay skipper appears to live only in tidal sawgrass marsh. Larval hostplant is unconfirmed but is probably sawgrass (Cladium sp.). There are two distinct flight periods, in late May and September. The separation between these suggests that the larvae may aestivate between the two, as well as hibernate during the winter. Both aestivation and hibernation are done as larvae, probably in the third or fourth instar.
Bay skipper has been recorded on coastal marshes in Mississippi and Texas. Although it is likely to be discovered at other sawgrass marshes along the Gulf coast, the lack of records from other states suggests that it does have a limited range.
Courtesy of Butterflies and Moths of North America, Big Sky Institute.
Because this species was only recently discovered, little is known about threats. However, because of its rarity and its use of coastal salt marsh habitat, over collection, natural disasters, and mosquito spraying are all potential threats.
Sawgrass marshes should be conserved and protected from disturbance (for example, mosquito spraying).
Additional surveys along the Gulf coast to identify other populations would be useful, as would life history studies. Currently, very little is known about this species. Careful documentation of the known habitat and identification of larval hostplant(s) and adult feeding behavior would be valuable.
Neck, R. W. 1996. A Field Guide to Butterflies of Texas. Gulf Publishing Co., Houston, TX.
Opler, P. A. (chair), J. M. Burns, J. D. LaFontaine, R. K. Robbins, and F. Sperling. 1998. Scientific Names of North American butterflies. Fort Collins, CO.
Opler, P. A., and V. Malikul. 1992. Eastern Butterflies. Peterson Field Guide. Houghton Mifflin Company, Boston, MA.
Shuey, J. A. 1989. The morpho-species concept of Euphyes dion with the description of a new species (Hesperiidae). Journal of Research on the Lepidoptera 27(3-4):161-171.
Shuey, John A. 1996. Another new EUPHYES from the southern United States Coastal Plain (Hesperiidae). Journal of the Lepidopterists’ Society 50(1):46-53.
Tveten, J., and G. Tveten. 1996. Butterflies of Houston & Southeast Texas. Univ. of Texas Press, Austin, TX.
Big Sky Institute, Butterflies and Moths of North America: bay skipper (Accessed 1/21/09)
Nearctica; The Butterflies and Skippers of North America: bay skipper (Accessed 5/10/05)
NatureServe Explorer (Accessed 9/23/08)
Vaughan, D. M., and M. D. Shepherd. 2005. Species Profile: Euphyes bayensis. In Shepherd, M. D., D. M. Vaughan, and S. H. Black (Eds). Red List of Pollinator Insects of North America. CD-ROM Version 1 (May 2005). Portland, OR: The Xerces Society for Invertebrate Conservation.