Our insect of the week for January 26, 2026 is the Io moth (Automeris io). It was described by Johann Fabricius in 1775.

This species is known throughout eastern North America including central Illinois. The adults are sexually dimorphic (males have bright yellow forewings whilst females have red-brown forewings). Males also have much larger antennae. Bats, birds, small mammals and spiders find these a tasty snack. Insect parasitoids include tachinid flies, ichneumonid wasps and brachonid wasps.

Caterpillars are protected by stinging spines which will release venom at the slightest touch. They feed on a number of host plants.

Adults have been observed in June and August in central Illinois.

The specimen in this photograph was collected by Gordon Adams in Peoria County, Illinois. Mark DuBois took the photo.