New Jersey Butterflies


Danaus plexippus

Identification: Large—3.8". Above: FW and HW orange with white-spotted black margins, and black veins crossing both wings. Males also have a small black scent patch along an inner HW vein. FW apex is black with pale orange spots. Below: FW bright orange with white-spotted black margin, black veins, and a black patch with white spots along leading edge. HW is a noticeably lighter bright buff, crossed by several heavy black veins and with white-spotted black margin. Larger than Viceroy and lighter below, and HW lacks median black line.

NJ Status and Distribution: Nonresident, but a common and widespread immigrant.

NJ Range Map-Monarch

Habitat: Open areas with wildflowers. Easily attracted to gardens with flowers such as milkweeds, Butterfly Bush, Purple Coneflower, asters, and goldenrods.

Flight Period: Arrival time in NJ is quite variable—some years as early as mid-April, other years not until mid-May. The last of the Mexico-bound fall migrants pass through in November. Extreme dates: North Jersey 4/15—11/29; South Jersey 4/11—12/31(1/12).

Larval Food Plants: Various native milkweeds (Asclepias), but also Tropical Milkweed grown in gardens.

Overwintering Stage: Adult, but does not overwinter in NJ.

Best Locations: Just about any open habitat. The biggest concentrations occur in Cape May and other coastal locations in fall, where hundreds of migrants can be seen nectaring on Seaside Goldenrod and garden flowers, and roosting in Eastern Redcedar trees. Large numbers of fall migrants can also be seen from the inland hawk watches.

Comments: Monarch is the most iconic butterfly of North America, and perhaps the most studied butterfly species in the world.


Male, Six Mile Run Reservoir Site, Somerset Co., NJ, 8/5/07.


Female, Blairstown, Warren Co., NJ, 9/11/10, on stonecrop.


Fredon Twp., Sussex Co., NJ, 8/19/09, on Brazilian Verbena.

Monarch larva

Egg on Orange Milkweed (Asclepias tuberosa).

Monarch larva

Mature larva on Common Milkweed (Asclepias syriaca).

Monarch larva

Late instar of Monarch feeding on seed pod of Common Milkweed (Asclepias syriaca).

Swamp Milkweed

Monarch nectaring on Swamp Milkweed (Asclepias incarnata). This is one of several species of milkweed that serve as host plants for Monarch caterpillars.

Butterfly Weed

Butterfly Weed or Orange Milkweed (Asclepias tuberosa), another host plant for Monarch caterpillars.

Purple Milkweed

Purple Milkweed (Asclepias purpurascens), another host plant for Monarch caterpillars.