Danaus gilippus

Sub-Family: Danaidae
Sub-Family Description: Milkweed Butterflies
Caterpillar: The caterpillar is brightly colored to discourage potential predators. It is black and marked with yellowish white rings in sets of three. It is also dotted with greenish yellow on the back and along the bottom edge of each side. There are three pairs of long filaments, resembling antennae: two towards the front and one at the rear. It reaches an average, full-grown length of two inches.
Adult: This is a large butterfly, with a wingspan of 3 to 3 7/8 inches. It is reddish brown on the upperside, edged with a dark brownish black border. The wing veins are outlined thinly in black. The forewing is spotted with white on the outer half, and there are two rows of smaller white dots in the dark border. The border of the hindwing may also have a few tiny white dots, and there may be white faintly clouding the wing veins (western individuals). Males have a patch of darker scent scales near the center of the hindwing. Underneath is colored and marked similarly, although the white dots may be more pronounced and the veins on the underside of the hindwing may be outlined thickly in black.

This species is a resident of southern California and Florida south to South America. It migrates north each year into portions of the U.S. as far north as northern Nevada, northern Idaho, southern North Dakota, and southern Iowa, and along the east coast north as far as North Carolina.

It occurs in open areas such as fields, open woodlands, and deserts.

Caterpillar: Caterpillars feed on the stems, leaves, and flowers of various species of milkweeds (Asclepias spp., Sarcostemma spp.).
Adult: Butterflies drink flower nectar, often from milkweeds. They may also obtain moisture and salts from mud.

There are several generations of caterpillars occurring all year long in the southern part of its range, and fewer are produced in the north. Queen caterpillars and butterflies, like the Monarch, are distasteful to most predators, due to noxious compounds obtained from feeding on milkweeds. Potential predators learn to avoid the brightly colored caterpillars and adults. Other "tasty" butterfly species, such as the dark Viceroy subspecies in the south, have come to mimic the Queen’s color pattern in order to take advantage of this predator avoidance. Butterflies may migrate northward in large numbers, and roost together in trees. Adults generally fly from July to August. The Queen can not survive freezing temperatures.

Males actively patrol in search of receptive females. They produce pheromones during courtship, which they direct towards the female using a brush (hair pencil) located at the tip of the abdomen. Females lay light green or white eggs singly on the stems, leaves, and flower buds of host plants.

Idaho Status: Unprotected nongame species.
Global Rank: G5
populations are widespread, abundant, and secure.

Ferris, C. D. and F. M. Brown. (eds.) 1981. Butterflies of the Rocky Mountain States. Univ. of Oklahoma Press, Norman, Oklahoma, USA, 442 pp.

Opler, P. A., H. Pavulaan, and R. E. Stanford. 1995. Butterflies of North America. Jamestown, North Dakota, USA: Northern Prairie Wildlife Research Center Home Page. http://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/bflyusa.htm (Version 05Nov98).

Opler, P. A. and A. B.Wright. 1999. A Field Guide to the Western Butterflies.   Second Edition.  Peterson Field Guide Series. Houghton Mifflin Company, New York, New York, USA, 540 pp.

Pyle, R. M. 1981. National Audubon Society Field Guide to North American Butterflies. Alfred A. Knopf, Inc., New York, New York, USA, 924 pp.

Scott, J. A. 1986. The Butterflies of North America. Stanford University Press, Stanford, California, USA, 583 pp.

Stanford, R. E. and P. A. Opler. 1993. Atlas of Western U.S.A. Butterflies (Including Adjacent Parts of Canada and Mexico). Published by authors, Denver, Colorado, USA, 275 pp.