Painted lady butterflies
(Vanessa cardui)

Painted lady butterfly larvae

When the caterpillars (butterfly larvae) arrive, do not allow your students to handle them because (a) the caterpillars are delicate and easily crushed, and (b) acids in perspiration on human fingertips may hamper the molting process.

If you must delay beginning the unit, you can store the caterpillars for up to one week in the vegetable bin of a lab refrigerator set at 40° to 50° F. This will retard their growth.

Warning: Keeping caterpillars colder than 40° F for more than one week jeopardizes both caterpillar and butterfly health, increasing the chances that the butterflies will emerge deformed.

The caterpillars are shipped with enough food to raise them. Follow the preparation instructions in The Life Cycle of Butterflies Teacher's Guide for preparing the caterpillar food. The painted ladies you and your students will raise are easily maintained in the classroom when fed this food. It is a mixture of plant materials plus vitamins and minerals.

Painted lady larvae and commercial food

Additional food information
The foods that caterpillars like best are plants in the mallow family. You might be able to find them in your schoolyard. Examples include rose of Sharon (Hibiscus syriacus), hollyhock (Althaea rosea), and marsh mallow (Althaea officinalis). Other plants that the caterpillars may eat include the leaves of thistle, nettle, sage, plantain, and dandelion. If possible, take a short field trip outdoors to collect some of these natural foods.

Safety reminder: Some thistles have sharp spines and some nettles have stinging hairs. Exercise caution when gathering these plants.

Painted lady eggs

Raising a second generation of painted lady butterflies
If you have discovered eggs in the cage, you are lucky. You have the opportunity to raise a second generation of butterflies and to experience the regenerative aspect of life cycles with your students.

Butterflies usually lay their eggs on the leaves of food plants favored by the caterpillars. But they will lay them on other things too, such as paper towels. Look for the eggs, and then collect them by removing the leaves or toweling from the cage. To avoid damaging the eggs, do not try to detach them from the leaves or toweling.
  

Have food available to the second generation of butterflies when they hatch. Any of the following are good choices:		Painted lady butterfly
•	the leftover food that came with the kit, which you stored in the refrigerator; or
•	fresh leaves of thistle, dandelion, sage, hibiscus, hollyhock, plantain, rose of Sharon, or sunflower.
As you know, the ravenous caterpillars will grow quickly, as will their appetites. Be sure to have a steady supply of food available if you undertake this project.