Extension Communications 3614 Administrative Services Building Ames, Iowa 50011-3614 (515) 294-9915

10/23/03

FOR IMMEDIATE RELEASE

Contacts:
Mary Harris, Reiman Gardens, (515) 294-2567, maharris@iastate.edu
Jean McGuire, Continuing Education and Communication Services, (515) 294-7033, jmcguire@iastate.edu

The Painted Lady

Mary Harris
Christina Reiman Butterfly Wing Curator

Last summer at Reiman Gardens, we provided a vast array of nectar flowers for butterflies throughout the 14 acres of outdoor gardens. By August, these beds were aflutter with the wings of various species of native butterflies, with Painted Ladies (Vanessa cardui) by far the most abundant.

As visitors walked by a bed of nectar plants, a veritable cloud of Painted Ladies would take flight and then settle down. The number of V. cardui observed throughout the Midwest this summer were extremely high. Previously, such high numbers of Painted Lady butterflies were observed in 1924, 1983, 1991, 1992 and 2001. These population peaks are common for many species of butterflies, yet the reasons are not completely understood.

Factors such as resources, parasite levels and weather the preceding winter have been suggested causes for the high population numbers periodically observed. After a population peak, the succeeding year often is characterized by extreme population lows, perhaps due to the high numbers of parasites produced during the peak.
The Painted Lady butterfly is native to all continents except the Antarctic (where no butterflies occur) and is likely to be the most abundant butterfly in the world. This worldwide distribution is the source for another common name, the Cosmopolitan. They also are known as the Thistle Butterfly, no doubt in reference to their preferred host and nectar plants in the genus Circium.

Although Painted Ladies may prefer thistle, their caterpillars are known to eat over 100 difference species of host plants. The majority of hosts are in the Asteraceae (including asters and thistles), Urticaceae (nettles), Malvaceae (mallows and hollyhocks), and Leguminaceae (peas and beans). In southern states, Painted Lady caterpillars can be a minor pest of the soybean. However, according to Donald Lewis, Iowa State University Extension Entomology Professor, this has never been the case in Iowa.

The wide range of plants suitable for consumption by Painted Lady caterpillars has allowed this species to be reared on artificial diets that are produced in powdered form and mixed with water, heated and portioned into rearing cups. There are several manufacturers of diet for Painted Ladies and these can be found easily on the Web. Artificial diets along with natural worldwide distribution have allowed Painted Ladies to become the only butterfly sold in the toy market and reared year round in children's classrooms. The butterfly lab at Reiman Gardens also takes advantage of the ease of rearing this species on an artificial diet and produces many of the Painted Lady butterflies on exhibit.

Painted Lady adults are medium-sized butterflies ranging from 1.7 to 3 inches in wingspan. The upper sides of the wings have areas of pinkish-orange with brown mottling. The pointed tips of the forewings are black with several patches of white. The hindwings are pinkish-orange with a row of five black circular spots toward the margin. The undersides of both the fore- and hindwings are mottled brown with ivory lines and a marginal row of four eyespots.

Males and females perform mating flights of fast figure eights. Females lay pale green eggs singly on the upper surface of a host plant leaf. The caterpillars are extremely variable in color but all have branched spines and hairs and feed individually, protected within a silken nest spun among host-plant leaves. The pupa is approximately 3/4 inch in length, grayish-brown with gold-tipped bumps. In addition to taking nectar from flowers, adults feed on tree sap and fermenting fruit. Placing a dish of fruit in your butterfly garden will attract not only Painted Ladies, but also several other native species with a similar predilection.

Painted Lady butterflies do not overwinter in Iowa. Instead, reproduction in both the female and male ceases in September and the adults migrate south to Texas and Mexico. This migration is not as strong nor as well studied as that of the Monarch (Danaus plexippus).

The vast majority of Painted Lady adults will remain in the northern states and succumb to the first killing frost. As I write this article in mid-October, I can still find some Painted Ladies in the Gardens, but not many and certainly not for long. From now until next May when migrant Painted Lady butterflies begin arriving from the south, I will have to satisfy my wish to see butterflies in flight by strolling through the Christina Reiman Butterfly Wing here at Reiman Gardens. In the Wing, I can see hundreds of butterflies of species from around the world, including the Painted Lady herself!

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Editors: Two color photos, suitable for publication, are available at right. Click on each thumbnail photo to go to the fullsized photo. The top picture's fullsize photo is 568K and the bottom picture's fullsize photo is 592K. Caption: Painted Lady Butterfly
Caption: Painted Lady catepillar and cocoon. Photo courtesy of Nathan Brockman, Reiman Gardens Insect Rearing Specialist

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