Monarch caterpillars develop best at 81 degrees F. This research was done in Canada several years ago. But they do fine if the temperature is between 70 degrees and 95 degrees F. I raise a small number of monarch butterflies, from egg to adult, every summer-usually around 10. Each caterpillar gets its own one quart glass canning jar, with a piece of fiberglass screen on the top, held down with a rubber band. The milkweed leaves are washed under cold water, and dried with a paper towel, before being given to the caterpillar. This helps to remove some of the pathogens that tend to accumulate in the local environment over the summer. Monarch cats are vulnerable to viruses, bacteria, & also single cell eukaryotes, one of which has a long name, ophryocystis elecktroschirrha, or something like that...They are also parasitized by certain flies, tachinid flies, that lay eggs on the caterpillar, and result in the eventual death of the monarch cat. So raising one cat per enclosure, washing leaves, and keeping the enclosures clean and dry helps maintain monarch health, and improves the odds, but does not guarantee success.

I haven't had much luck raising gulf fritillaries inside. Don't know what goes wrong, they just don't make it.

I always disinfect my cages, and any supplies used, after the butterflies have emerged. I make up a solution of bleach and water (about 1/4 cup bleach to 4 gallons water) and soak the cage for 10 minutes on each side, then rinse well and set in the sun to help dissipate any bleach that may remain.