Moths of North Carolina

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View PDF	Saturniidae Members:	Anisota Members:	170 NC Records

Anisota stigma (Fabricius, 1775) - Spiny Oakworm Moth

Taxonomy

Superfamily:
Bombycoidea

Family:
Saturniidae

Subfamily:
Caratocaminae

P3 Number:
890014

MONA Number:
7716.00

Comments: One of four species in this genus that occurs in North Carolina (3 others occur north of Mexico -- Tuskes et al. 1996)

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: Adult males are distinctive. Compared to the males of other species of Anisota, they are unique in possessing opaque reddish wings with dark specklings and a well-defined, if diffuse, postmedian line; they are the only males that fly during the night and that are attracted to lights. Some confusion might be possible with male Sphingicampa bicolor, but the inner margin of the forewing is much shorter than the outer margin in Anisota species, whereas it is nearly equal in length in Sphingicampa (Forbes, 1923). Adult females differ from S. bicolor in this same respect, and the speckling on their forewings is shared among Anisota species only by A. senatoria. Female A. stigma can be distinguished from A. senatoria by the presence of a well-defined medial line on the hindwing and by similar coloration on both sets of wings; in senatoria, the hindwings are typically paler than the forewings. Photographs showing only the forewings may not provide enough information to separate these two species, but female A. stigma tend to be darker colored and possess more extensive speckling; they also are usually larger and have broader wings.

Wingspan: 45 mm, males; 60 mm, females (Forbes, 1923)

Adult ID Requirements: Identifiable from photos showing hindwings, abdomen, or other specialized views [e.g., frons, palps, antennae, undersides].

Immatures and Development: Larvae -- Spiny Oakworms -- like other members of this genus, have two prominent, black thoracic spines. Last instars are easy to recognize by their lack of longitudinal stripes and by the presence of numerous small white tubercles scattered all over the body and horns (Ferguson, 1971; Wagner, 2005).

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

Distribution in North Carolina

Distribution: Probably found throughout the state except at high elevations where oaks are uncommon

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: Single brooded, flying primarily in mid-summer

Habitats and Life History

Habitats: Probably associated with most types of oak forests in the state. The majority of our records come from upland habitats, particularly dry-to-xeric sandhills in the Coastal Plain, where they may feed predominantly on Turkey oak, and monadnocks in the Piedmont (in the Northeast, this species is now more or less restricted to barrens habitats; Wagner, 2005). However, we also have records from lowlands and mesic slopes from across the state, indicating some use of non-xerophytic oaks.

Larval Host Plants: Larvae are oligophagous, feeding primarily on oaks, including Northern Red Oak (Quercus rubra) and Turkey Oak (Q. laevis), but have also been reported on hazel (Corylus) and basswood (Tilia) (Ferguson, 1971; Wagner, 2005). In North Carolina, larvae have been observed feeding on Blackjack Oak (Q. marilandica). - View

Observation Methods: Both sexes come fairly well to blacklights and incandescent lights. Adults do not feed and consequently do not come to bait. Spiny oakworms feed more solitarily than other species of Anisota, are less likely to have outbreak years, and are generally more difficult to find (Tuskes et al., 1996)

Wikipedia

See also Habitat Account for General Oak-Hickory Forests

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 has been extirpated from 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 Anisota stigma - Spiny Oakworm Moth

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

	Recorded by: David George on 2025-06-29 Moore Co. Comment:		Recorded by: David George on 2025-06-29 Richmond Co. Comment:
	Recorded by: Jim Petranka, Mark Basinger and Becky Elkin on 2025-06-29 Richmond Co. Comment:		Recorded by: Jim Petranka, Mark Basinger and Becky Elkin on 2025-06-29 Richmond Co. Comment:
	Recorded by: Jim Petranka, Mark Basinger and Becky Elkin on 2025-06-29 Richmond Co. Comment:		Recorded by: Jim Petranka, Mark Basinger and Becky Elkin on 2025-06-28 Moore Co. Comment:
	Recorded by: Mark Basinger on 2025-06-25 Buncombe 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: Mark Basinger on 2025-06-23 Buncombe Co. Comment:
	Recorded by: Stefanie Hedrick on 2024-08-29 Union Co. Comment:		Recorded by: A. Garton on 2024-07-30 Moore Co. Comment:
	Recorded by: A. Kauppila on 2024-07-03 Burke Co. Comment:		Recorded by: Mark Basinger on 2024-06-30 Rowan Co. Comment:
	Recorded by: Jim Petranka on 2024-06-29 Madison Co. Comment:		Recorded by: Mark Basinger on 2024-06-29 Rowan Co. Comment:
	Recorded by: Mark Basinger on 2024-06-29 Rowan Co. Comment:		Recorded by: Tina Fulcher on 2024-06-27 Davidson Co. Comment:
	Recorded by: Tina Fulcher on 2024-06-27 Davidson Co. Comment:		Recorded by: Tina Fulcher on 2024-06-27 Davidson Co. Comment:
	Recorded by: Owen McConnell on 2024-06-26 Graham Co. Comment:		Recorded by: Owen McConnell on 2024-06-26 Graham Co. Comment:
	Recorded by: Emily Stanley on 2024-06-23 Buncombe Co. Comment:		Recorded by: Mark Basinger on 2024-06-23 Yancey Co. Comment:
	Recorded by: Laura Graham on 2024-06-17 Gaston Co. Comment:		Recorded by: Laura Graham on 2024-06-17 Gaston Co. Comment:
	Recorded by: Dean Furbish on 2024-06-16 Wake Co. Comment:		Recorded by: John Petranka on 2023-07-28 Orange Co. Comment:
	Recorded by: Chuck Smith on 2023-07-22 Davidson Co. Comment:		Recorded by: Chuck Smith on 2023-07-20 Davidson Co. Comment: