Phoebis sennae
Identification: Medium—2.5” (much larger than Clouded Sulphur). Rarely seen basking with open wings. Below: Male FW and HW bright yellow with scattered small dark smudges. Female is darker yellow with many larger, purplish spots, including an obvious thick streak across the mid-FW.
NJ Status and Distribution: Nonresident. Primarily a southern species that occurs as a regular stray in NJ, some years in large numbers. Reported from throughout the state but most frequently seen from Monmouth and Burlington counties south.
Habitat: Open, sunny, areas. Will visit gardens with flowers such as Butterfly Bush, Purple Coneflower, asters, goldenrods, and milkweeds.
Flight Period: Generally July into November but most seen in August and September. Rarely seen before June or after November. Extreme dates: North Jersey 5/15-11/18; South Jersey 5/13-12/16.
Caterpillar Food Plants: Sennas (Senna) and Partridge Peas (Chamaecrista).
Overwintering Stage: Not known to overwinter in NJ.
Good Locations: Higbee Beach WMA, Cattus Island CP, Sandy Hook GNRA, Cape May Point SP, Assunpink WMA, Thompson Park (Middlesex County).
Comments: Numbers of this striking butterfly vary considerably from year to year.