New York Natural Heritage Program
Mottled Duskywing
Erynnis martialis (Scudder, [1870])
Mottled Duskywing Steve Walter
Family: Skippers (Hesperiidae)

State Protection: Species Of Special Concern
A native species at risk of becoming Threatened; does not qualify as Endangered or Threatened, but have been determined to require some measure of protection or attention to ensure that the species does not become threatened. NYSDEC may regulate the taking, importation, transportation, or possession of any Species of Special Concern as it deems necessary.

Federal Protection: Not Listed

State Rarity Rank: S1
A State Rarity Rank of S1 means: Typically 5 or fewer occurrences, very few remaining individuals, acres, or miles of stream, or some factor of its biology makes it especially vulnerable in New York State.

Global Rarity Rank: G3
A Global Rarity Rank of G3 means: Either rare and local throughout its range (21 to 100 occurrences), or found locally (even abundantly at some of its locations) in a restricted range (e.g. a physiographic region), or vulnerable to extinction throughout its range because of other factors.

Did you know?
This skipper is thought to be extirpated from most of its range east of the Mississippi River, with a few colonies remaining in New York, Canada, and probably in the southern Appalachians and Great Lakes region. The main foodplant of the larva was once so common that it was commercially important as New Jersey Tea, especially around the time of the American Revolution. Now the plant is so reduced that this skipper and two moths whose larvae feed on the leaves are probably gone from that state and much of the east. The Albany Pine Bush is probably the only place in the Northeast where all three still occur. Excessive browsing by deer and loss of brushy and barrens habitats are among the factors in this decline. The recent well-known populations on the southeastern Pennsylvania serpentine barrens apparently disappeared in the early or mid 1990s following a few years of heavy browsing of the foodplant by deer. The deer herd was reduced, the plants recovered, but with no known populations remaining closer than the Albany, New York Pine Bush, the Mottled Duskywing is not expected to return there.

State Ranking Justification [-]
This skipper still occurs in the Albany Pine Bush and two additional preserves. However, it is unlikely that any sites are actually protected from deer. The foodplants are now known to be exclusively Ceanothus spp., which are favored by deer and deer have apparently caused the extirpation of colonies of this skipper in other states. This skipper has declined dramatically in Ohio and Canada and probably no longer occurs in any other states near New York, from New Hampshire through at least eastern Pennsylvania.

Short-term Trends [-]

Long-term Trends [-]