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.
Pink bollworm. The pink bollworm (Pectinophora gossypiella), Spanish: lagarta rosada, is an insect known for being a pest in cotton farming. The adult is a small, thin, gray moth with fringed wings. The larva is a dull white, eight-legged caterpillar with conspicuous pink banding along its dorsum. The larva reaches one half inch in length. The pink bollworm is native to Asia, but has become an invasive species in most of the world's cotton-growing regions.