In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many forms of polymerization and different systems exist to categorize them.
The thistle caterpillar is the larval stage of the painted lady butterfly. The adult insect migrates into Iowa each year from Texas and Mexico. Eggs are laid on both thistle and soybeans. The caterpillar is easily identified by the spines that resemble Christmas trees that have lost all their needles.
Caterpillars feed on specific plants that we refer to as their host plants. Each species of butterflies have their own particular host plants. For example, Monarch caterpillars feed only on Milkweeds. Most caterpillars feed on leaves, but some will also eat the flowers and seeds.