Automeris

Pronunciation

How to pronounce Automeris: //ɔːtəˈmɪərɪs//

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Images

Summary

The Io moth (Automeris io) is a colorful nocturnal moth recognized by its distinctive eyespots and sexual dimorphism, with a lifecycle that includes a gregarious caterpillar stage and transformation into a fluffy adult that does not feed.

Physical Characteristics

Imagines (sexually mature, reproductive stage) have a wingspan of 2.5–3.5 inches (63–88 mm). Males have bright yellow forewings, while females have reddish-brown to purple forewings. Males possess larger plumose (feathery) antennae. Both sexes have one black to bluish eyespot on each hindwing, with possible variations due to hybridizations.

Identification Tips

Look for the distinctive large black to bluish eyespot on the hindwings and the sexual dimorphism in wing coloration—yellow in males and reddish-brown to purple in females.

Habitat

Found in a variety of habitats including deciduous forests, where host plants are available for larval feeding.

Distribution

Ranges from the southeast corner of Manitoba, southern extremes of Ontario, Quebec, New Brunswick, Nova Scotia in Canada, and in the US from Montana, North Dakota, South Dakota, Nebraska, Colorado, New Mexico, Texas, Utah, and down to southern Florida.

Diet

Caterpillars are herbivorous and primarily feed on the leaves of host plants such as mulberry, pin cherry, willow, and others.

Life Cycle

Females lay eggs in clusters on host plants. The caterpillars go through five instars and spin a cocoon to pupate. Adults emerge and are primarily nocturnal.

Reproduction

Mating occurs at night, with females emitting pheromones to attract males. After mating, females lay eggs and die shortly thereafter.

Predators

Io moths are preyed upon by birds, small mammals, and spiders.

Conservation Status

Not evaluated for listing on the IUCN Red List and has no special status on the U.S. Federal List. Eastern populations indicate a declining trend.

Ecosystem Role

As both herbivores (caterpillars) and prey for various predators, Io moths play a role in their ecosystem's food web.

Cultural Significance

The name Io references a figure from Greek mythology, reflecting cultural ties and narratives associated with the species.

Health Concerns

Contact with the caterpillar's stinging spines can cause irritation and dermatitis (erucism) in humans.

Collecting Methods

• Netting adults at night using light traps
• Searching for larvae on host plants

Preservation Methods

• Keeping specimens in insect boxes
• Using alcohol for preservation of specimens

Misconceptions

Although they have venomous spines, encounters with Io moth larva are generally not life-threatening to humans.

Tags

• Automeris
• Io moth
• Saturniidae
• Lepidoptera
• Nocturnal moth