THE FUNEREAL DUSKYWING, ERYNNIS FUNERALIS (HESPERIIDAE): SEASONAL RANGE EXPANSION INTO EASTERN NORTH AMERICA.

The accepted normal range of the funereal duskywing skipper, Erynnis funeralis (Hesperiidae), is generally considered to be the southwestern United States, Mexico, Central America, and western South America from Colombia to northern Argentina and Chile. According to various records, however, adult funeralis have been observed in a variety of locations throughout the eastern half of central North America, sometimes thousands of kilometers outside its accepted range. These individuals are usually conceptualized as non-reproductive strays, but different lines of evidence (e.g. the observations of both males and females, the fresh condition of most adults, the recurrence of observations in the same locations at similar times of year in different years) suggest that funeralis regularly establishes seasonal breeding populations in the eastern half of central North America. To test this hypothesis, I examined reports of observations of funeralis throughout this region for evidence of 1) regular as opposed to random presence in the East, 2) eastern as opposed to western eclosion, 3) regular as opposed to random expansion throughout the East, and 4) reproductive activity. The results revealed evidence of all four phenomena. Consequently, I concluded that instead of being conceptualized as an irregular, non-reproducing stray, funeralis should be conceptualized as a regular seasonal immigrant that establishes temporary breeding populations in the eastern half of central North America during the warmer months of the year. [ABSTRACT FROM AUTHOR]