Caterpillar Care Tips:
- Correct Host Plant.
Most butterflies lay their eggs on a small group of closely related plants. These host plants are the only food that the caterpillars can eat. Most will starve to death rather than eat other foliage. So it is very important that you provide the proper host plant for your caterpillar. For example, Monarch caterpillars eat only plants in the milkweed genus, Red Admiral caterpillars eat nettles and false nettles, and Black Swallowtail caterpillars eat plants in the carrot family such as parsley, fennel and dill. Most butterfly field guides will provide a list of host plants for each butterfly species.
- Fresh Leaves.
Caterpillars can not eat leaves that have become dry or too wilted. Use potted host plants or place cut stems in water to keep them fresh and palatable for a longer period of time.
- Do Not Move While Molting.
As caterpillars grow they must shed their old skins as they become too tight. The caterpillar spins a silk pad, grips the silk with its feet, and then literally crawls out of the old tight skin. If the hold on the silk pad is torn loose at the wrong time, the caterpillar may not be able to complete the process. It is safe to handle caterpillars that are actively eating or moving. But if the caterpillar is still, especially if it has moved off of the host plant and is firmly attached to a surface, it should not be removed from that surface.
- Keep The Cage Clean.
Caterpillars are little eating machines and they produce a lot of droppings called frass. It is not good for caterpillars to live in their own waste, so clean the cage daily or as needed.
- Avoid Condensation On Inside of Cage.
Caterpillars like high humidity, but not moisture in the form of condensation. Placing paper toweling in the bottom of the cage will help absorb excess moisture. If condensation forms, provide increased air flow or reduce the number of caterpillars in the container. The caterpillars are prone to a variety of illnesses and the disease organisms flourish in overly humid conditions indicated by condensation.
- Avoid touching or disturbing new chrysalises.
After anchoring itself to a silk pad, the caterpillar sheds it's skin for the last time to reveal the chrysalis within. The newly formed chrysalis is very soft and is easily damaged by handling. The surface hardens and toughens with time. So just leave the new chrysalis alone for two days to give it time to harden before moving or handling it.
- A place for the butterfly to expand its wings.
When the butterfly emerges from the chrysalis it must immediately be able to hang with its wings down. This enables it to pump fluid from its abdomen down the veins in the wings to expand the wings. The wings start to harden in just a few minutes and will be permanently deformed if the butterfly fails to expand them. Usually the butterfly will cling to the empty chrysalis. Just in case it falls, it is important that it be able to crawl back up into a hanging position. Provide rough surfaces along the sides of a smooth walled cage to avoid trapping the new butterfly in the bottom and be sure that the container is tall enough so that the wings will not touch the bottom when the butterfly hangs from the empty chrysalis.
- More information.
A great resource book with complete rearing instructions is Rick Mikula’s The Family Butterfly Book.