Painted Lady Caterpillars

Painted lady butterflies are members of the Nymphalidae family, also known as brush-footed butterflies. This is the largest group of butterflies and gets its name because the first pair of legs is smaller than the other four legs. Painted lady usually refers to members of the Vanessa cardui species. However there is also an American painted lady (Vanessa virginiensis) and an Australian painted lady (Vanessa kershawi).

The painted lady (V. cardui) is the most widely distributed butterfly in the world. It can be found on every continent except Antarctica. In the United States, it can be found year round in the Southwest. In the summer, it migrates to the Midwest and eastern United States. The American Painted Lady (V. virginiensis) is typically only found in North America, although a few have been found in parts of Europe. Caterpillars of either species can be found anywhere food is available, although they prefer open areas such as fields or prairies.

Painted lady caterpillars will eat more than 100 different species of plants. Its host plants include asters and thistles (Asteraceae spp.); nettles (Urticaceae spp.); malva, mallow and hollyhock (Malvaceae spp.); and legumes (Leguminaceae spp.). It is considered a minor pest of soybeans. It is known to favor thistles and hollyhock.

Painted lady caterpillars hatch from pale green, barrel-shaped eggs about four days after the eggs are laid on the host plant. After hatching, larvae create a silken web nest in which to live and feed. Caterpillars vary in color, but all have branched spines and hairs along their backs. Caterpillars remain in this stage for 12 to 18 days and will shed their skins about five times. They then form a J-shape in preparation for entering the pupa stage. Painted lady chrysalises are 3/4 inch long and grayish-brown with yellow bumps. Butterflies emerge from their chrysalises after 10 days.

The painted lady is one of the most popular insects raised in the classroom. Caterpillars sold to classrooms are usually raised, not collected from the wild, and about 5 to 10 days old. They should be kept in a location that is warm (room temperature) away from direct sunlight and any drafts. Commercial food can be purchased to feed the caterpillars, or host plants can be collected. If collecting plants, care should be taken to select plants that are free from pesticides and other chemicals. After the butterfly emerges from the chrysalis, it should be kept in a cage large enough to allow it fly and be fed sugar water in small dish with a sponge placed inside it. Although adult butterflies can be released, it is not recommended. The butterfly will live about two weeks.