Moths of North Carolina

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View PDF	Crambidae Members:	Diathrausta Members:	46 NC Records

Diathrausta harlequinalis Dyar, 1913 - Harlequin Webworm Moth

Taxonomy

Superfamily:
Pyraloidea

Family:
Crambidae

Subfamily:
Pyraustinae

Tribe:
Spilomelini

P3 Number:
80a1083

MONA Number:
5175.00

Comments: This is a wide-ranging species that occurs from California to the East Coast and exhibits substantial geographic variation. Munroe (1956) recognized four subspecies that need additional study.

Species Status: "Not sure these two [reconditalis and harlequinalis] are really different" (Scholtens, 2017)

Identification

Field Guide Descriptions: Beadle and Leckie (2012)

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

Technical Description, Adults: Munroe (1956)

Adult Markings: In this species the head, thorax, abdomen, and ground color of the forewings and hindwings are black. The forewing has a faint dull-yellow antemedial line that contrast with the white reniform, orbicular, and claviform spots. There is an off-white triangular mark on the costa and a faint dull-yellow line (often obscure or missing) that extends for a short distance from the inner margin near the middle of the wing. The fringe is white except for a sub-tornal black region and has a narrow black line at the base. The hindwing has a narrow white line that runs from below the tornus to a more prominent white discal spot. The fringe is similar to that of the forewing.

Diathrausta reconditalis is similar to D. harlequinalis but the white markings on both wings are smaller and less distinct than those on D. harlequinalis, at least in North Carolina populations. Some specimens may not be distinguishable based on color and patterning and require dissection. Size is also helpful, with the wingspan being 16 mm or less in D. reconditalis and 18-22 mm in D. harlequinalis.

Wingspan: 18-22 mm (Munroe, 1956).

Adult Structural Features: Munroe (1956) has an illustration of the male genitalia and noted that the spine on the sacculus ventrad to the base of the clasper is much wider and less strongly acute in D. reconditalis than in D. harlequinalis. Also, see images below.

Genitalia and other structural photos

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

Immatures and Development: The larval life history is undocumented.

Distribution in North Carolina

Distribution: As currently recognized, Diathrausta harlequinalis is widely distributed across the U.S. from southern Maine to southern Florida, and westward to southern California, southern Arizona, New Mexico, Oklahoma, Colorado, Illinois and Minnesota. It also occurs in southern Ontario and Quebec. As of 2023, we have records from all three physiographic provinces, with most from the Piedmont and lower elevations in the Blue Ridge.

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
Flight Comments: The adults have been observed from March through October in Florida, and mostly from June through September in more northern areas of the range. As of 2023, we have records from early May through late-September.

Habitats and Life History

Habitats: Specimens have been observed in North Carolina in habitats ranging from xeric Sandhills communities to mesic cove forests in the mountains. Many are from semi-wooded residential neighborhoods.

Larval Host Plants: The plant hosts (if any) are undocumented. - View

Observation Methods: The adults are attracted to lights.

Wikipedia

Status in North Carolina

Natural Heritage Program Status:

Natural Heritage Program Ranks:

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

Comments:

Photo Gallery for Diathrausta harlequinalis - Harlequin Webworm Moth

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

	Recorded by: Mark Basinger on 2025-10-03 Rowan Co. Comment:		Recorded by: Marilyn Westphal on 2025-09-07 Henderson Co. Comment:
	Recorded by: R. Teper, David George, P. Coin, K. Bischof on 2025-08-16 Transylvania Co. Comment:		Recorded by: Emily Stanley on 2025-08-11 Buncombe Co. Comment:
	Recorded by: Will Bennett on 2025-07-26 Avery Co. Comment: iNat record - At least two observed, photos are different individuals. Seen directly adjacent to possible host Capnoides sempervirens. 4100 ft elevation. https://www.inaturalist.org/observations/302512468 https://www.inaturalist.org/observations/302512458		Recorded by: Will Bennett on 2025-07-26 Avery Co. Comment: iNat record - At least two observed, photos are different individuals. Seen directly adjacent to possible host Capnoides sempervirens. 4100 ft elevation. https://www.inaturalist.org/observations/302512468 https://www.inaturalist.org/observations/302512458
	Recorded by: Mark Basinger on 2025-06-25 Buncombe Co. Comment:		Recorded by: Mark Basinger on 2025-06-25 Buncombe Co. Comment:
	Recorded by: Jim Petranka on 2024-09-11 Madison Co. Comment:		Recorded by: Jim Petranka on 2024-08-25 Madison Co. Comment:
	Recorded by: Dean Furbish, Lior S. Carlson on 2024-08-12 Pamlico Co. Comment:		Recorded by: Lior S. Carlson, Dean Furbish on 2024-08-12 Pamlico Co. Comment:
	Recorded by: Jim Petranka on 2024-08-11 Madison Co. Comment:		Recorded by: Jim Petranka on 2024-08-01 Madison Co. Comment:
	Recorded by: Jim Petranka on 2023-09-26 Madison Co. Comment:		Recorded by: Jim Petranka on 2023-09-24 Madison Co. Comment:
	Recorded by: Jim Petranka, Bo Sullivan and Becky Elkin on 2023-09-14 Macon Co. Comment:		Recorded by: Jim Petranka on 2023-08-02 Madison Co. Comment:
	Recorded by: Owen McConnell on 2022-09-08 Graham Co. Comment:		Recorded by: John Petrankaj on 2022-08-25 Orange Co. Comment:
	Recorded by: David George, L. M. Carlson on 2022-07-30 Orange Co. Comment:		Recorded by: Jim Petranka on 2022-07-29 Madison Co. Comment:
	Recorded by: Jim Petranka on 2022-07-22 Madison Co. Comment:		Recorded by: Jim Petranka on 2022-07-17 Madison Co. Comment:
	Recorded by: tom ward on 2022-05-22 Buncombe Co. Comment:		Recorded by: David George, L. M. Carlson on 2022-05-03 Orange Co. Comment:
	Recorded by: David George, L. M. Carlson on 2021-09-11 Orange Co. Comment:		Recorded by: Jim Petranka on 2021-08-25 Madison Co. Comment:
	Recorded by: David George, L. M. Carlson on 2021-08-21 Orange Co. Comment:		Recorded by: Dean Furbish on 2021-08-08 Wake Co. Comment: