Moths of North Carolina

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View PDF	Crambidae Members:	Herpetogramma Members:	48 NC Records

Herpetogramma theseusalis (Walker, 1859) - No Common Name

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Taxonomy

Superfamily:
Pyraloidea

Family:
Crambidae

Subfamily:
Pyraustinae

Tribe:
Spilomelini

P3 Number:
80a1028

MONA Number:
5279.00

Comments: Over 20 species of Herpetogramma have been described from North America that are based mostly on external morphology. The most recent treatment consolidates these into only nine species (Solis, 2010) and all nine occur in North Carolina.

Species Status: The rolled leaf shelters that this species uses for feeding and protection from predators and parasitoids are important microhabitats for a variety of invertebrates. Jennings et al. (2017), for example, found 36 species of spiders that used shelters in Maine.

Identification

Field Guide Descriptions:

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

Technical Description, Adults: Forbes (1923, as Phylctaenia theseusalis); Solis (2010)

Adult Markings: In this species the head, thorax and abdomen are concolorous with the forewing and hindwing ground color, which varies from warm brown to yellowish brown. The abdomen has a narrow white crossband on the posterior margin of each segment, and the forewing has dark brown to brownish-black marks that contrast with the ground color. The marks include a faint, circular, orbicular spot and a more prominent reniform that is curved or kidney-shaped. The area between the two lacks a whitish patch that is seen is some of our Herpetogramma species. The antemedial line is weakly sinuous and bends basally just before reaching the costa. The costa has dark shading from the base to the postmedial line, and the subterminal area lacks prominent dark shading, but is often a shade darker than the general ground color.

The postmedial projects inward from the costa at around three-fourths the wing length. The section near the costa is straight, then meets an outwardly bulged section with three small, rounded teeth. From there the line projects basally and forms a rounded bend near the adjoining reniform spot, then runs relatively straight and obliquely inward to meet the inner margin near the middle of the wing. The hindwing is generally similar, but lacks the antemedial line and has a single discal spot. The postmedial lines of both wings are bordered distally by a narrow, diffuse light tan band. The fringe of both wings is a shade lighter than the adjoining ground color, and there is a narrow, dark brown, marginal line on both the forewing and hindwing.

Herpetogramma centrostrigalis closely resembles H. theseusalis, but the latter is smaller, duskier, and has lines and spots that are darker and more contrasting. The subterminal area is also usually a shade darker than the overall ground color, as opposed to being concolorous in H. centrostrigalis. In addition, the line between M2 and the costa is relatively straight, as opposed to being curved on H. centrostrigalis. Patania silicalis is also similar, but lacks an orbicular spot. In addition, the area immediately behind the postmedial line is not conspicuously lighter than the overall ground color.

Wingspan: 25–27 mm (Handfield and Handfield, 2021).

Forewing Length: 11-14 mm (Solis, 2010).

Adult Structural Features: Handfield and Handfield (2021) have descriptions and illustrations of the male and female genitalia.

Structural photos

Adult ID Requirements: Identifiable from good quality photos of unworn specimens.

Immatures and Development: Much like H. sphingealis, the larvae of this species produce globular shelters on ferns ('fern balls') that are used for feeding and as a defense against parasitoids and predators. LoPresti and Morse (2013) reported that overwintering larvae at a study site in Maine emerge from the leaf litter in the spring, then ascend newly unfurled fern fronds and construct roughly spherical shelters. The shelters are about 2–3 cm in diameter and are made at night by rolling the apical end of a frond downward, notching the rachis, and binding pinnae (leaflets) to the outside of the structure with silk. The larvae feed from the inside of the shelters, and a given individual may construct two or more additional shelters during the larval period as they grow. The larvae pupate within the shelter, with the pupal stage lasting around two weeks.

Distribution in North Carolina

Distribution: Herpetogramma theseusalis is broadly distributed across eastern North America. It occurs in southeastern Canada from Ontario eastward to Nova Scotia and vicinity. From there the range encompasses much of the eastern US east of the Mississippi River to as far south as southern Florida. Isolated populations have been found farther west in Minnesota, southern Louisiana, and eastern Texas. This species occurs statewide in North Carolina, with most records from the Coastal Plain and Piedmont.

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: The adults of this wide-ranging species have been found from April through November, with peak activity occurring in July. As of 2023, we have records from early-June through late-October, with Coastal Plain adults on the wing a few weeks earlier than those in the Piedmont and Blue Ridge. Local populations in North Carolina appear to produce two or three generations per year, with the larvae from the last brood overwintering in the soil.

Habitats and Life History

Habitats: The larva use several species of ferns that are generally associated with moist grounds.

Larval Host Plants: Several fern species are documented hosts (Forbes, 1923; LoPresti and Morse, 2013; Solis, 2010; BugGuide). Potential hosts in North Carolina include the Sensitive Fern (Onoclea sensibilis), Marsh Fern (Thelypteris palustris), Royal Fern (Osmunda spectabilis), Interrupted Fern (Claytosmunda claytoniana) and Cinnamon Fern (Osmundastrum cinnamomeum). As of 2025, the majority of our records are for Cinnamon Fern, along with records for Virginia Chain-fern (Anchistea virginica), Netted Chain-fern (Lorinseria areolata) and Royal Fern. J.B. Sullivan also recorded a larva on Sweetleaf (Symplocos tinctoria), which appears to be an atypical host. - View

Observation Methods: The adults are attracted to lights and can be reared from fern balls.

Wikipedia

See also Habitat Account for General Wet Fernlands

Status in North Carolina

Natural Heritage Program Status:

Natural Heritage Program Ranks: GNR S3S5

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

Comments: This species appears to be relatively uncommon throughout the state, perhaps because of its reliance on Cinnamon Fern and other fern hosts that frequent moist habitats and wetlands.

Photo Gallery for Herpetogramma theseusalis - None

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

	Recorded by: Mark Basinger on 2025-09-12 Wilson Co. Comment:		Recorded by: Allison Garton on 2025-08-29 Moore Co. Comment:
	Recorded by: Allison Garton on 2025-08-29 Moore Co. Comment:		Recorded by: Allison Garton on 2025-08-29 Moore Co. Comment:
	Recorded by: Mark Basinger on 2025-08-25 Wilson Co. Comment:		Recorded by: Mark Basinger on 2025-08-21 Wilson Co. Comment:
	Recorded by: Mark Basinger on 2025-08-19 Wilson Co. Comment:		Recorded by: David George, Jeff Niznik, Rob Van Epps, Kevin Metcalf on 2025-07-20 Richmond Co. Comment:
	Recorded by: David George, Jeff Niznik, Rob Van Epps, Kevin Metcalf on 2025-07-20 Richmond Co. Comment:		Recorded by: David George on 2025-06-29 Richmond Co. Comment:
	Recorded by: Mark Basinger on 2025-06-28 Wilson Co. Comment:		Recorded by: Mark Basinger on 2025-06-11 Wilson Co. Comment: Fern balls were on Lorinseria (Woodwardia) areolata.
	Recorded by: Mark Basinger on 2025-06-11 Wilson Co. Comment:		Recorded by: Mark Basinger on 2025-06-07 Wilson Co. Comment: On Royal Fern.
	Recorded by: Mark Basinger on 2025-06-07 Wilson Co. Comment:		Recorded by: Mark Basinger on 2025-05-30 Bladen Co. Comment:
	Recorded by: Jim Petranka and Becky Elkin on 2025-05-24 Richmond Co. Comment:		Recorded by: Dean Furbish on 2025-04-29 Pender Co. Comment:
	Recorded by: Dean Furbish on 2025-04-29 Pender Co. Comment:		Recorded by: Mark Basinger on 2024-09-12 Wilson Co. Comment:
	Recorded by: Mark Basinger on 2024-06-20 Bladen Co. Comment: Anchistea (Woodwardia) virginica and Osmundastrum cinnamomeum were two host ferns.		Recorded by: Mark Basinger on 2024-06-19 Columbus Co. Comment:
	Recorded by: Mark Basinger on 2024-06-18 Brunswick Co. Comment:		Recorded by: Jeff Niznik on 2024-06-14 Scotland Co. Comment:
	Recorded by: Mark Basinger on 2024-04-28 Columbus Co. Comment: Osmundastrum cinnamomeum, also observed on Anchistea (Woodwardia) virginica.		Recorded by: Erich Hofmann and CFCC BIO146 Students on 2024-04-26 Brunswick Co. Comment:
	Recorded by: Erich Hofmann and CFCC BIO146 Students on 2024-04-26 Brunswick Co. Comment:		Recorded by: Simpson Eason on 2023-09-23 Brunswick Co. Comment:
	Recorded by: David George, L. M. Carlson on 2022-07-26 Greene Co. Comment:		Recorded by: Darryl Willis on 2021-10-22 Cabarrus Co. Comment: