Moths of North Carolina
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Halysidota Members:
90 NC Records

Halysidota harrisii Walsh, 1864 - Sycamore Tussock Moth

Halysidota harrisii
view caption 		Halysidota harrisiiHalysidota harrisiiHalysidota harrisii
Taxonomy
Superfamily:
Noctuoidea		 Family:
Erebidae		Subfamily:
Arctiinae		Tribe:
Arctiini		P3 Number:
930361		 MONA Number:
8204.00
Comments: One of five species in this genus that occur in North America (Lafontaine and Schimdt, 20010), three of which have been recorded in North Carolina
Identification
Field Guide Descriptions: (Not in either field guide)Online Resources: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIF, BOLDTechnical Description, Adults: Forbes (1960)Technical Description, Immature Stages: Forbes (1960); Wagner (2005)                                                                                 
Adult Markings: Adults of all three of our species of Halysidota are highly similar to one another, possessing long, pointed wings that are translucent yellow and marked with bands of slightly darker, offset cells forming a tessellated pattern. The markings of H. harrisii and H. tessellaris are virtually identical and cannot be identified from photographs; only examination of male specimens can be used for reliable identification of adult H. harrisii.
Adult Structural Features: Males of Halysidota harrisii can be distinguished from H. tesselaris by the slightly different shapes to the tips of their valves, which can be seen by brushing away the scales at the ends of the abdomens (see illustration in Forbes, 1960, and Watson, 1980). In H. tesselaris, the upper, costal process extends farther distally than the lower, saccular process, with the situation reversed in H. harrisii. The valves of H. tessellaris are also less incurved than those of H. harrisii, which can sometimes be detected without dissection. No characters are known that separate females of these two species.
Adult ID Requirements: Identifiable from photos showing hindwings, abdomen, or other specialized views [e.g., frons, palps, antennae, undersides].
Immatures and Development: Larvae, in contrast to the adults, are easy to tell apart: those of Halysidota harrisii are yellowish or white with white and rust colored anterior pencils; those of H. tesselaris are yellowish-brown to gray, with conspicuous white and black pencils at the anterior end (Forbes, 1960; Wagner, 2005).
Larvae ID Requirements: Identifiable from good quality photos, especially where associated with known host plants.
Distribution in North Carolina
Distribution: Based on larval records, it appears to be widespread and relatively common in the Piedmont and low mountains. Uncommon in (or absent from) the high mountains and much of the coastal plain, except possibly along brownwater rivers where sycamore occurs.
County Map: Clicking on a county returns the records for the species in that county.
Halysidota harrisii
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: Wagner (2005) states that Halysidota harrisii has two flights over most of its range. This is probably the case in North Carolina, but we do not have enough adult records to detect any clear patterns. The far more common larval records do seem to suggest distinct summer and fall generations.
Habitats and Life History
Habitats: Riparian forests, including brownwater river floodplains in the Coastal Plain and bottomland hardwoods more generally in the Piedmont and Low Mountains.
Larval Host Plants: Larvae are believed to feed solely on American Sycamore (Platanus occidentalis) (Forbes, 1960; Wagner, 2005), which has been confirmed as the host in North Carolina. Other reported hosts are most likely in error. - View
Observation Methods: Comes to blacklights in small numbers even in areas that appear to be prime habitat, but whether that is due to lack of attraction to lights or small population sizes is unknown. May feed on flowers similarly to H. tessellaris, but none have been caught at bait. Looking for larvae blown down from Sycamores by storms appears to be the best method of searching for this species.
Wikipedia
See also Habitat Account for Rich Wet Hardwood Forests
Status in North Carolina
Natural Heritage Program Status:
Natural Heritage Program Ranks: G4 SNR [S4?]
State Protection: Has no legal protection, although permits are required to collect it on state parks and other public lands. Should possibly be placed on the NHP Watch List until more is learned about its actual distribution and abundance
Comments: This species is certainly a habitat specialist but appears to be even rarer than would be expected based on the distribution of Sycamore in the state. We have inspected hundreds of adult specimens with all but a tiny fraction turning out to be H. tessellaris, even in areas where Sycamore is common or at sites where we have definite records of their presence. The reason for this rarity (or apparent rarity) is unknown.

 Photo Gallery for Halysidota harrisii - Sycamore Tussock Moth

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

Recorded by: Reginald J Jones II on 2025-06-20
Cumberland Co.
Comment: 		Recorded by: Reginald J Jones II on 2025-06-20
Cumberland Co.
Comment:
Recorded by: Reginald J Jones II on 2025-06-20
Cumberland Co.
Comment: 		Recorded by: Mark Basinger on 2025-06-06
Wilson Co.
Comment:
Recorded by: Andrew W. Jones on 2024-09-27
Polk Co.
Comment: 		Recorded by: David George on 2024-09-08
Durham Co.
Comment:
Recorded by: A. Kauppila on 2023-10-05
Burke Co.
Comment: 		Recorded by: Stephen Dunn on 2023-09-25
Orange Co.
Comment:
Recorded by: David George, Jeff Niznik on 2023-09-20
Durham Co.
Comment: 		Recorded by: Andrew W. Jones on 2023-09-19
Polk Co.
Comment:
Recorded by: John Petranka on 2023-09-16
Orange Co.
Comment: 		Recorded by: David George on 2023-09-10
Orange Co.
Comment:
Recorded by: David George on 2023-09-08
Durham Co.
Comment: 		Recorded by: Andrew W. Jones on 2023-09-04
Macon Co.
Comment:
Recorded by: David George, Jeff Niznik on 2023-09-04
Orange Co.
Comment: 		Recorded by: Jim Petranka and Becky Elkin on 2023-08-31
Buncombe Co.
Comment:
Recorded by: John Petranka on 2023-07-21
Durham Co.
Comment: 		Recorded by: Dean Furbish on 2022-09-04
Wake Co.
Comment:
Recorded by: Jim Petranka and Becky Elkin on 2022-08-25
Clay Co.
Comment: 		Recorded by: Morgan Freese on 2022-07-04
Buncombe Co.
Comment:
Recorded by: Jim Petranka on 2022-06-26
Madison Co.
Comment: 		Recorded by: Jim Petranka on 2021-08-21
Madison Co.
Comment:
Recorded by: L. Knepp on 2021-07-21
Surry Co.
Comment: 		Recorded by: Aimee on 2021-06-15
Guilford Co.
Comment:
Recorded by: Aimee on 2021-06-15
Guilford Co.
Comment: 		Recorded by: Aimee on 2021-06-15
Guilford Co.
Comment:
Recorded by: J. Thomson on 2020-10-10
Durham Co.
Comment: 		Recorded by: Jim Petranka on 2020-08-12
Madison Co.
Comment:
Recorded by: Jim Petranka on 2020-08-12
Madison Co.
Comment: 		Recorded by: Jim Petranka on 2020-08-12
Madison Co.
Comment: On the underside of an American Sycamore leaf.