Hylephila phyleus (Drury 1773)
Status: Frequent nonoverwintering resident.
Flight: First strays from the south in June. The offspring of these migrants constitute the bulk of the Iowa flight, which occurs from early August through late October.
Distinguishing features: Adults are tan-orange. Males have a prominent stigma with a gray shadow toward the rear. Dark fingerlike projections form a ragged border above. Females are larger and darker, with a nearly solid border above; the lower hind wing has a dark stipe in the area of the anal veins, with small dark patches throughout. Wingspan: 2.7 - 2.9 cm. (males) to 3.3 cm. (females).
Distribution and habitat: Map 155 .Observed across the entire state, but most encounters have taken place in the western half. Adults are encountered in a wide variety of native and created habitats and often frequent flower gardens.
Natural history: The Fiery Skipper is not tolerant of Iowa winters, and populations are probably killed off each year. Caterpillars feed on weedy grasses such as crabgrass and Bermuda grass.
Questions: Do larval or adult Fiery Skippers ever overwinter in Iowa? Is this species more frequent in western Iowa, or is this simply an artifact of the activities of butterfly observers? What environmental factors might account for the higher frequency of the migratory animal in the west?