Biology of the rare skipper, Problema bulenta (Hesperiidae), in southern New Jersey

The rare skipper, Problema bulenta (Boisduval & Leconte), was first recognized as occurring in southern New Jersey in 1989, although the first specimen was collected in 1983. Through the summer of 1992, it has been found in five counties along the Delaware bayshore and the Atlantic coast, with Burlington Co. the northern limit. We collected two larvae in the field on Spartina cynosuroides (L.) Roth (Poaceae), and reared one to maturity on the same host. Adults occur in tidal marshes containing S. cynosuroides , but have been observed only in the vicinity of nectar plants, not in patches of the larval host. Adults may become highly concentrated on nectar plants at some sites; we have counted as many as 121 individuals on flowers in ten minutes at one locality. It is not yet possible to say whether the New Jersey populations are secure.