When hatching butterfly eggs, there are three basic things to remember:
- Will the egg collapse and perish if it doesn't remain attached to the original leaf it was laid on?
- When the egg develops and hatches as a young first instar caterpillar, will that young caterpillar cannibalize other eggs it finds?
- Does the egg require humidity to hatch? (Most from the Western U.S. do not)
The answers to these two questions depends on the species of butterfly and will drive the best setup to hatch out butterfly eggs. This section will address the principle and provide examples whereas the Taxa Specific section will tell you exactly how to hatch certain species of butterflies.
Some butterfly species overwinter as egg. Those eggs will require an "overwintering treatment" and is addressed in the overwintering techniques page.
More often than not, the larvae of many butterfly species in the U.S. are not considered to be cannibalistic. Therefore, it is more practical to remove the eggs from the plant they were laid on and combine them in a single hatching container. When they hatch, simply place on larval host plant.
Some species of butterflies have caterpillars that are cannibalistic if they find other eggs. In this event, it is imperative to place eggs individually into separate containers (small solo cups work great.)
The eggs of some species of butterflies can collapse or perish if they are cut out from the original leaf they were laid on, even if the egg remains in tact on the cut-out portion of this original leaf.
When the leaf section dries up with the egg attached, the hatch rate of eggs on some of these species can be negatively affected. Therefore, it is best to keep the egg on the original leaf it was laid on while keeping the leaf as succulent as possible either as a cutting or on potted host.