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.
Caterpillar -. They are 1.5 mm long with dark heads and dark spotted whitish bodies on hatching. Young ones are 10-20 mm long and pale yellow, greenish or brownish with dark heads, hairs on their upper body and often have dark narrow stripes along the backs and sides of the body.