Pieris rapae
Identification: Small—1.7”. Above: Male mostly white with dark smudges at FW tips and one black spot on FW. Females similar but with 2 black spots in FW. Below: FW black spots often covered by HW. Individuals with light yellowish hindwings below are fairly common. Some spring individuals with reduced black spots can look almost completely white, and thus are sometimes mistaken for West Virginia Whites, which have not been reported in NJ for many years.
NJ Status and Distribution: Resident. Probably the most common and ubiquitous butterfly in NJ and 1 of 2 non-native species (the other is European Skipper). This is the small white butterfly that one sees patrolling fields and roadsides everywhere. It is common in every county.
Habitat: Everywhere except interior woodland.
Flight Period: Several overlapping broods resulting in one extended flight period from mid-March to October. Extreme dates: North Jersey 1/29—11/30; South Jersey 2/27—12/31.
Caterpillar Food Plants: Plants in the Mustard Family, including garden vegetables and crops.
Overwintering Stage: Pupa.
Good Locations: Anywhere and everywhere.
Comments: This is one of just a few species of butterfly that can be reliably identified while driving 70 mph in NJ. In the western U.S., where several similar-looking species occur, it’s a different story.
Male, High Point SP, Sussex Co., NJ, 9/13/11, on White Snakeroot.
Female, Wallkill River NWR, Sussex Co., NJ, 6/23/05.
Unmarked spring form, Sandy Hook, Monmouth Co., NJ, 5/4/17.
Kay Environmental Ctr., Morris Co., NJ, 7/11/06, on Spotted Knapweed.
Fredon Twp., Sussex Co., NJ, 8/15/10, on Hoary Mountainmint.
Glenhurst Meadows, Somerset Co., NJ, 6/29/12.
Walpack Twp., Sussex Co., NJ, 8/3/12, on Spotted Knapweed.
Howell Twp., Monmouth Co., NJ, 7/29/08, on Spotted Knapweed.
Caterpillar on Bok Choy.
Pupa.