New Jersey Butterflies

Swarthy Skipper

Nastra lherminier

Identification: Tiny—FW <0.5". Sexes similar on both surfaces. Above: FW and HW usually unmarked blackish-brown, rarely with 2 faint spots in the mid-FW. Below: FW and HW unmarked dull yellowish-brown, with paler veins that become less obvious as the butterfly becomes old and worn. Similar skippers: Tawny-edged lacks the pale veins. European: When worn can easily be misidentified as a Swarthy, but "Euros" are orange above and finish flying by the end of July.

NJ Status and Distribution: Resident. Uncommon and local in northern counties, where it is usually encountered in very small numbers; seldom seen at higher elevations. More common and widespread from Middlesex and Mercer counties south, where dozens or even hundreds may be seen in a day.

NJ Range Map-Swarthy Skipper

Habitat: Dry, grassy fields. In South Jersey also in bogs.

Flight Period: Two broods from late May—early July and early August—mid-September in the north; mid-June—early July and early August—late September in the south. Extreme dates: North Jersey 5/22—9/30; South Jersey 5/23—10/30.

Larval Food Plants: Little Bluestem grass (Schizachyrium scoparium).

Overwintering Stage: Mature larva.

Best Locations: Big Brook Park, Negri-Nepote Native Grassland Preserve, Assunpink WMA, Willowwood Arboretum, Lakehurst Bog, Higbee Beach WMA, Cape May Bird Observatory CRE garden.

Comments: When a grass-skipper lacks any prominent identifying field marks, think Swarthy, but until the end of July beware of worn Europeans.



Swarthy Skipper

Lakehurst, Ocean Co., NJ, 6/19/09, on Large Cranberry.


Swarthy Skipper

Big Brook Park, Monmouth Co., NJ, 8/22/04.