Moths of North Carolina
Scientific Name:
Common Name:
 Family (Alpha):
« »
View PDFCrambidae Members:
Herpetogramma Members:
31 NC Records

Herpetogramma theseusalis (Walker, 1859) - Herpetogramma Moth


view caption
view caption
Taxonomy
Superfamily: Pyraloidea Family: CrambidaeSubfamily: PyraustinaeTribe: SpilomeliniP3 Number: 801200.00 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 Photographs: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIF, BOLDTechnical 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 that 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.
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