Adults are active from late spring to early autumn. Their wings are a drab gray color, but their bright yellow bodies are marked with rows of black spots on the sides. Females lay fertilized eggs in clusters on milkweed leaves. Newly hatched caterpillars begin as yellowish tubes with tiny black heads and are covered in white wispy hairs. They immediately begin chewing up milkweed leaves, leaving the veins behind. As caterpillars progress through their instars, colorful character takes over. The simple white hairs grow longer and the caterpillar gets covered in a mostly black coat. This is accented with bright orange-red hairs that almost form rings around each segment. Sets of long, white lashes project out of the head and rear. They are voracious eaters at every stage and can skeletonize a milkweed plant if decent numbers of them are present. Two broods can be produced in one year.
Look for Milkweed Tussock Moths anywhere milkweed grows. This includes parks, gardens, roadsides, fields, and meadows.