Moths of North Carolina

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Automeris io (Fabricius, 1775) - Io Moth

Taxonomy

Superfamily:
Bombycoidea

Family:
Saturniidae

Subfamily:
Hemileucinae

Tribe:
Hemileucini

P3 Number:
890055

MONA Number:
7746.00

Comments: One of seven species in this genus found north of Mexico but the only one found east of the Appalachians (Tuskes et al., 1996). Ferguson (1971) recognized two subspecies along the Atlantic Slope: Automeris io io from Maine to South Carolina and A. io lilith from South Carolina to Florida and west to Louisiana. Tuskes et al. (1996), however, did not find any consistent geographic differences between these forms and did not recognize lilith as a distinct subspecies.

Identification

Field Guide Descriptions: Covell (1984); Beadle and Leckie (2012)

Online Resources: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIF, BOLD

Technical Description, Adults: Forbes (1923), Ferguson (1971), Tuskes et al. (1996)

Technical Description, Immature Stages: Forbes (1923), Ferguson (1971), Covell (1984), Tuskes et al. (1996), Wagner (2005)

Adult Markings: Adults are unmistakeable: medium-large moths with yellow (males) or reddish-brown (females) forewings and large black, pale-centered eyespots on the hindwings.

Wingspan: 60 mm, males; 80 mm, females (Forbes, 1923)

Adult ID Requirements: Unmistakable and widely known.

Immatures and Development: The larvae, with their branched stinging spines, are only likely to be confused with those of the Buck Moth. Late instars are mostly green and possess a white-and-red stripe along the sides; in the Buck Moth, larvae are mostly dark brown, densely flecked with white dots, with some possessing a broad white stripe along the sides but no red striping (Wagner, 2005).

Larvae ID Requirements: Identifiable from good quality photos, especially where associated with known host plants.

Distribution in North Carolina

Distribution: Probably statewide except possibly the Outer Banks and other barrier islands.

County Map: Clicking on a county returns the records for the species in that county.


Flight Dates: High Mountains (HM) ≥ 4,000 ft. Low Mountains (LM) < 4,000 ft. Piedmont (Pd) Coastal Plain (CP) Click on graph to enlarge
Immature Dates: High Mountains (HM) ≥ 4,000 ft. Low Mountains (LM) < 4,000 ft. Piedmont (Pd) Coastal Plain (CP) Click on graph to enlarge
Flight Comments: Double-brooded in the Coastal Plain and possibly the Piedmont but apparently single-brooded in the Mountains.

Habitats and Life History

Habitats: The Io moth occupies a wide variety of habitats throughout its range, including residential areas and croplands in addition to natural ecosystems (Ferguson, 1971; Tuskes et al., 1996; Wagner, 2005). In North Carolina, records are missing from the Outer Banks and barrier islands but otherwise include xeric sandhills and wet savanna, peatland, and bottomland habitats in the Coastal Plain; upland forests and lakeshores in the Piedmont, and dry to mesic slopes in the Low and High Mountains.

Larval Host Plants: Larvae are broadly polyphagous, feeding on many species of hardwood trees, shrubs, forbs, and graminoids, but not on conifers, however (Ferguson, 1971; Wagner, 2005). In North Carolina, larvae have been recorded feeding on White Oak (Quercus alba), Water Oak (Q. nigra), River Birch (Betula nigra), hickory (Carya), Lespedeza, Wax-myrtle (Morella cerifera), Sourwood (Oxydendrum arboreum), Sassafras (Sassafras albidum), dogwood, and Winged Elm (Ulmus alata). It likely also uses many other genera of host plants in our state. See the below link for an extensive list of host plants. - View

Observation Methods: Adults of both sexes come well to blacklights and incandescent lights but since they do not feed, they do not come to bait. Larvae are gregarious in the earlier instars and are often quite conspicuous. Pupation occurs in leaf litter.

Wikipedia

See also Habitat Account for General Forests and Fields

Status in North Carolina

Natural Heritage Program Status:

Natural Heritage Program Ranks: G5 SNR [S5]

State Protection: Has no legal protection, although permits are required to collect it on state parks and other public lands

Comments: Populations are locally vulnerable to the effects of weather, outbreaks of disease, parasites, and predators, and to the effects of pesticides. However, given the commonness of their host plants, wide habitat range -- including suburban areas -- and statewide distribution, this species can easily recover from localized losses. In the Northeast, however, this species is declining and becoming more localized in Connecticut and other areas where it once occurred (Wagner, 2012), possibly due to parasitism by a Tachinid fly, Compsilura concinnata, that was widely introduced in the Northeast to control Gypsy Moths and other pest Lepidoptera. This fly represents a serious and pervasive threat for many species of moths and is suspected to be responsible for the marked declines in several Saturniids. While such impacts have not yet been documented in North Carolina, Compsilura has spread as far south as Virginia (Kellogg et al., 2003) and will probably continue to expand its range southward. The situation in North Carolina needs to be monitored.

Photo Gallery for Automeris io - Io Moth

171 photos are available. Only the most recent 30 are shown.

	Recorded by: David George, Jeff Niznik on 2025-09-14 Durham Co. Comment:		Recorded by: David George, Jeff Niznik on 2025-09-14 Durham Co. Comment:
	Recorded by: Jim Petranka and Becky Elkin on 2025-08-18 Madison Co. Comment:		Recorded by: Allison Garton on 2025-08-17 Moore Co. Comment:
	Recorded by: Stephen Dunn on 2025-08-10 Orange Co. Comment:		Recorded by: K. Hutson on 2025-07-23 Gaston Co. Comment:
	Recorded by: David George, Jeff Niznik on 2025-07-20 Moore Co. Comment:		Recorded by: Jim Petranka, Mark Basinger and Becky Elkin on 2025-06-28 Moore Co. Comment:
	Recorded by: Jim Petranka, Mark Basinger and Becky Elkin on 2025-06-25 Mitchell Co. Comment:		Recorded by: Mark Basinger on 2025-06-23 Buncombe Co. Comment:
	Recorded by: Jim Petranka and Mark Basinger on 2025-06-23 Buncombe Co. Comment:		Recorded by: K. Bischof on 2025-06-22 Transylvania Co. Comment:
	Recorded by: K. Bischof on 2025-06-19 Transylvania Co. Comment:		Recorded by: A. Kauppila on 2025-06-18 Burke Co. Comment:
	Recorded by: Ken Kneidel on 2025-06-16 Mecklenburg Co. Comment:		Recorded by: Jim Petranka on 2025-05-06 Madison Co. Comment:
	Recorded by: Mark Basinger on 2025-05-03 Brunswick Co. Comment:		Recorded by: Mark Basinger on 2025-05-03 Brunswick Co. Comment:
	Recorded by: Mark Basinger and Miles Buddy on 2025-04-26 Brunswick Co. Comment:		Recorded by: Mark Basinger on 2025-04-25 Columbus Co. Comment:
	Recorded by: Mark Basinger on 2025-04-25 Columbus Co. Comment:		Recorded by: Mark Basinger on 2025-04-25 Columbus Co. Comment:
	Recorded by: Mark Basinger on 2025-04-25 Columbus Co. Comment:		Recorded by: Chuck Smith on 2025-04-16 Bladen Co. Comment:
	Recorded by: Jim Petranka, Mark Basinger and Becky Elkin on 2024-09-21 Madison Co. Comment: Larva was feeding on Winged Elm.		Recorded by: B. Bockhahn on 2024-07-14 Macon Co. Comment:
	Recorded by: David George, Jeff Niznik on 2024-07-08 Chatham Co. Comment:		Recorded by: David George, Jeff Niznik on 2024-07-08 Chatham Co. Comment:
	Recorded by: David George, Jeff Niznik, Stephen Dunn on 2024-06-29 Chatham Co. Comment:		Recorded by: Owen McConnell on 2024-06-28 Graham Co. Comment: