Dusted skipper

DISTRIBUTION AND HABITAT

The dusted skipper is found east of the Rockies from southeastern Canada and northern New Mexico east to central New England and Florida. The dusted skipper is absent from large areas of this range. For example, they are absent from the southeastern coastal plain, and much of New York and Pennsylvania. In New Jersey, it is widespread though usually seen in small numbers.

The dusted skipper's habitat is bluestem grasslands, woods openings in acid pine or pine-oak barrens, and prairie remnants. The ideal habitat is one in which the food plant grass is the dominant grass, intermixed with patches of bare sand or rock. Bluestems are often found on rock outcrops and man-made sites, such as old fields, power line corridors, airports, old railway beds, and even highway edges. The dusted skipper is often found in such locations, and thus appears tolerant of habitat disturbance as long as its host plant is present.

DIET

Caterpillar host plants are little bluestem and big bluestem. Adult butterflies feed from the nectar from flowers including Japanese honeysuckle, wild strawberry, blackberry, wild hyacinth, phlox, vervain, and red clover.

LIFE CYCLE

The eggs of the dusted skipper are bright yellow and tan at the top. They have a smooth texture with very small holes. The larva are a pink-lavender color on the top with grayish sides and covered with long yellowish hairs. Green and brown larva have also been reported. During the larval stage they form a tent-like structure by fixing several leaves together using silk at the base of its host plant. Once the larva goes into the chrysalis phase it turns a pale brown color with pink and orange tones on the abdomen. During this phase it is smooth and cylindrical.

Dusted skippers are primarily “univoltine”, meaning they have one brood per year. Their one brood each year usually occurs between May and June in its northern range. However, in Florida, populations are known to have two brood periods. Mature caterpillars overwinter encased within sealed leaves near the base of the host plant.

CURRENT STATUS, THREATS, AND CONSERVATION

The dusted skipper is currently listed as secure globally, though it might be quite rare in parts of its range. The dusted skipper’s numbers may be increasing in many parts of its southern range. In contrast, the dusted skipper is in decline across much of its mid-western range, because of widespread destruction of natural prairie habitats as well as excessive prescribed burning in prairies.

The dusted skipper seems limited mainly by its univoltine biology and the availability of suitable dry little bluestem-dominant grasslands. In order to preserve populations of dusted skipper, proper management of dry grassy habitats are needed. These habitats are often managed through prescribed burning. But burning likely kills immature forms and it is not known how well dusted skipper re-colonizes after a burn, so this grassland management technique should not be used unless adequate unburned areas are left nearby. Frequent burning has been detrimental to dusted skipper in many states.

In 2015, the New Jersey Endangered and Nongame Advisory Committee recommended a Special Concern status for this species within the state, but no formal rule proposal has been filed to date.

Text written by Michael Colella in 2015.