Slug caterpillars
Many slug caterpillars live in Missouri. The early button slug looks like a green fruit that's going rotten in the middle. This caterpillar grows to about 1/2 inch and feeds on basswood, birch, cherry, chestnut and other woody shrubs and trees. The cocoon might overwinter in a cool garage. The mature caterpillars are found in July and August. The shagreened slug is a pretty, oval, light blue green slug with a creamy dorsal stripe. It grows to about 3/4 inch long and can be found in the forests of Missouri. It eats beech and oak but has also been seen on hornbeam and hickory trees. Mature caterpillars are found from May till frost.
Skippers
Skippers tend to have caterpillars with robust bodies and large, hard, round heads. The northern cloudy wing has two or more broods in Missouri. The larva grows to 1 1/4 inches long and can be found in the forests, fields, grasslands and meadows. It eats legumes, including beggar's ticks and bush clover. The caterpillar has a large dark head and a pale green to brown body freckled with creamy spots. Mature caterpillar are found in July and August. The European skipper is different from other skippers in that it has two white lines on its head. The body is pale green blue with white stripes and a green stripe. It grows to 1 inch long and can be found in fields, grasslands, woodlands and forest clearings in northeastern Missouri. It eats grasses, including velvet grass and timothy grass.
Geometers
The Esther moth can have many color patterns, but is usually brownish-red marked with green yellow lines or white to mimic the twigs of the pine trees that are its food plant. It grows to 1 1/2 inches long. There two broods in Missouri with mature caterpillars occurring from March till frost. The crocus geometer is a caterpillar that grows to 1 3/4 inches long. It lives in fields, wetlands and other open habitats in east central Missouri. It feeds on low growing plants and shrubs. Mature caterpillar are found from April into late summer.
Ceratocampinae
Ceratocampinae is a subfamily that includes the imperial and royal moths and oak worms. The imperial moth larvae can be extremely variable. Some are brown, some are green, some are brilliant red or chocolate brown, but all of them have long setae and white spiracles on the side. They can be found in barrens and woodlands, and have two generations in Missouri. The caterpillars can grow to over 3 inches, and mature caterpillars can be found from July to November. Their food plants are basswood, birch, cedar, elm, maple, oak, pine and other woody species. The spiny oak worm also has two generations in Missouri and also has highly variable colors, from orange to yellow-brown to almost black. It has the same habitat as the imperial moth, and one generation of mature caterpillars can be found from July to November. It grows to around 2 1/2 inches long, and eats oak, hazel and basswood.