Insects of Iowa
Insect Orders
Information Page
Life Cycle Page
Moths of Iowa
Promethea Moth
The pictures show the various stages of the life cycle of the moth. Pictures 1 shows the eggs, 2-19 show the various instars of the caterpillars. The caterpillars go through 4-5 instars as they grow larger. They shed their skin each time and form a larger skin to go into. The Promethea caterpillars are more gregarious than others. They stay in groups until the last couple instars. The pictures show how they change as they get to maturity in color and shape. Picture 15 shows the head extended. Most of the time the head is with drawn into the first segment. Picture 20 show the caterpillar starting to form the cocoon. Picture 21 shows the male and 22 the female. Most of the other silkmoths look similar in the male and female and sex is determined by checking the antennae. Males will have larger, more feathery antenna than the females.
 Caterpiller forming cocoonMale
FemaleMating (Female hatched from a cocoon I found attracted a male in my backyard)