New Jersey Butterflies

Juniper Hairstreak

Callophrys gryneus

Identification: Very small—size of thumbnail. Almost never seen with wings open. Below: FW and HW bright green (when fresh) with bold white postmedian lines bordered with brown on inner side only. Upper ends of postmedian bands are straight. Appears quite brownish when heavily worn. Similar hairstreaks: NJ's only other green hairstreak is Hessel's, which may appear a bluer-green, and has brown on both sides of the postmedian bands, and a displaced spot at the upper end of each band. Hessel's is generally confined to the immediate vicinity of southern NJ Atlantic White Cedar bogs, while Juniper is much more widely distributed in upland fields with Eastern Redcedar.

NJ Status and Distribution: Resident. Generally uncommon and local throughout.

NJ Range Map-Juniper Hairstreak

Habitat: Open areas near host plant. Can easily be attracted to gardens that are near stands of the host plant. Prefers to nectar at milkweeds and mints.

Flight Period: Two broods from early April to mid-September, but mainly late-April to late May; and early July to mid-August. Extreme dates: North Jersey 4/9-10/22; South Jersey 3/27—10/12.

Larval Food Plants: Eastern Redcedar (Juniperus virginianus), a native evergreen tree of advanced upland successional fields/young forests.

Overwintering Stage: Pupa.

Best Locations: Sandy Hook NRA, Flatbrookville, Jenny Jump SF (Summit Trail).

Comments: Some years, in North Jersey at least, the spring brood is small or absent.

Juniper Hairstreak

Fredon Twp., Sussex Co., NJ, 7/13/07, on Hoary Mountain-Mint.