The caterpillars and the plant have co-existed for a long time. As the caterpillars grow and mature, they disperse to other nearby secondary foodplants, such as lousewort or even small young ash sprouts. When fully grown, the caterpillars frequently choose to rest on a woody stem before shedding their last skin and becoming a chrysalis. By the time the adults have emerged and mated, the turtlehead is about two or three feet tall and is ready to receive the next generation of checkerspots. A female Baltimore Checkerspot will lay a single layered patch of one hundred to five hundred eggs on the underside of a turtlehead leaf.
Egg laying takes a day or two and provides a good opportunity for close observation and photography.
After hatching, the caterpillars feed in a communal web until about half grown, and then those that have survived move into the leaf litter to wait for the spring, when they will resume feeding. If you live reasonably close to an established colony, the chances are quite good that your turtlehead will nurture some of these orange and black beauties. A group of several plants will be more readily found by the Baltimores and, in flower, will be visually attractive to humans. Seeds require cold stratification. This is most easily accomplished by planting seeds in the fall.