Io Moth

The Io Moth (Automeris io) is a colorful North American moth with a rather toxic larvae. The adult moths are either yellow or reddish depending upon their sex. Males of the species are smaller in size and yellow is their dominant color. Females are much larger than the males and are a lovely reddish hue. Both sexes have large, brilliant eyespots on their under-wings that they flash when threatened.

The adults emerge from their pupae lacking mouth-parts and do not feed in this stage of their life. Subsisting only on stores of nutrients that were ingested as larvae, their adult life-spans are fairly short.

Eggs are laid in clusters on host plants and the larvae that emerge are brilliant green with a white lateral stripe and are covered in stinging spines. Caterpillars host on a variety of species including hackberry (Celtis), willow (Salix), mesquite (Prosopis), redbud (Cercis), currant (Ribes), blackberry (Rubus), and pear (Pyrus). Larvae of the Io Moth are extremely irritant to humans and all contact should be avoided. Larvae are at first gregarious feeders that move in long trains and only venture off to feed singly in later instars.