Moths of North Carolina

Scientific Name:	Common Name:		Family (Alpha):

View PDF	Yponomeutidae Members:	Yponomeuta Members:	94 NC Records
Yponomeuta multipunctella Clemens, 1860 - American Ermine Moth

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Taxonomy

Superfamily: Yponomeutoidea	Family: Yponomeutidae	Subfamily: Yponomeutinae	Tribe: [Yponomeutinae]	P3 Number: 36a0123	MONA Number: 2420.00
Comments: Y. multipunctella is one of five species of Yponomeuta that occur north of Mexico. Three North American species (Y. euonymella, Y. leucothorax, and Y. semialba) are no longer recognized and are treated as Y. multipunctella (Lewis and Sohn, 2015). A fourth species (Y. atomocella) was transferred to the genus Prays. Four of the five currently recognized North American species of Yponomeuta are introduced, and some have become defoliating pests of apples, cherries and ornamental Euonymus species.

Identification

Field Guide Descriptions: Covell (1984); Beadle and Leckie (2012)

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

Technical Description, Adults: Lewis and Sohn (2015); microleps.org

Adult Markings: Adults are white with 3-4 rows of black dots. Y. cagnagella is an introduced species that resembles Y. multipunctella, but has fewer black dots, particularly near the middle of the forewing. This species is a pest on ornamental Euonymus species and was first recorded in North America from Ontario in 1967. Y. cagnagella has since spread to the northern US and south to Delaware and Maryland. It could potentially reach North Carolina in the future.

Wingspan: 17-20 mm (Covell 1982).

Structural photos

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

Immatures and Development: Caterpillars can be found in early spring before the adults first appear, suggesting that the eggs overwinter and hatch as the host plants begin their spring growth. The larvae feed in small communal webs, primarily on the shoots of American Strawberry-bush (Euonymus americanus). Individual bushes that have been observed in North Carolina often have most shoots covered with webs, and a single web typically contains fewer than 10 larvae. In many cases, individual plants can be heavily defoliated by foraging caterpillars during the spring months. Many older instar larvae leave the communal webs, but some remain and pupate beneath the webbing (microleps.org; Covell, 1984).

Jim Petranka found larvae in Madison Co. that were pupating communally on the undersides of low-lying vegetation within 15 cm of the ground surface. The nests were within 3 meters of E. americanus shrubs where the earlier instars fed. The larvae constructed communal nests by folding 1-3 leaves under with silk. They then spun very thin whitish cocoons within the silk refuge. The nests contained from 2-30 pupae and were construct using the leaves of Golden Ragwort (Packera aurea), Red Maple, and Southern Red Oak. The larvae presumably dropped or crawled from the overlying Euonymus foliage, then managed to locate other larvae or pupae, perhaps by using scent trails. In a different year, larvae were observed pupating within the folded leaves of a Maple-leaf Viburnum (Viburnum acerifolium). The leaf folds were located 5-6 feet above the ground and each contained a single larva or pupa. The late-instar larvae appeared to have migrated from a nearby E. americanus plant to the Viburnum. The adults began emerging about two weeks after the leaf folds were collected.

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

Distribution in North Carolina


Distribution: Almost all records are from the Piedmont and Blue Ridge where the host species are most common.
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, with a peak in June.

Habitats and Life History

Habitats: Populations are restricted to areas that support the host plants, which are Euonymus species (Sperling et al. 1995, Ulenberg 2009). The primary host is the American Strawberry-bush (Euonymus americanus). This species is widespread in mesic to rich forests, but also occurs to a lesser extent in both floodplain forests and drier pine-oak and oak-hickory forests. Two other native Euonymus (E. atropurpureus; E. obovatus) are uncommon and presumably serve as secondary hosts where local populations occur. Several species ofEuonymus from Europe and Asia are widely planted as ornamentals in the eastern US, but Y. multipunctella does not use these as host plants.

Larval Host Plants: Larvae feed on Euonymus, including American Strawberry-bush (Euonymus americanus), Eastern Wahoo (E. atropurpureus), and Running Strawberry-bush (E. obovatus) (Godfrey et al., 1987; Beadle & Leckie, 2012). In North Carolina, larvae have been recorded feed on American Strawberry-bush, and have often been found pupating in the leaves of nearby plants. - View

Observation Methods: This species is easily detected by examining Euonymus americanus in early spring for the distinctive communal webs. The adults readily come to black lights.

Wikipedia

See also Habitat Account for General Mesic Hardwood Forests

Status in North Carolina

Natural Heritage Program Status:

Natural Heritage Program Ranks: G5 [S4S5]

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

Comments: The American Ermine Moth is rather common in the Piedmont and Blue Ridge, but populations have undoubtedly been adversely affected by White-Tailed Deer. Deer feed heavily on the primary host plant (E. americanus) and can eliminate or nearly eliminate local populations of the host plant where grazing pressure is high. Yponomeuta cagnagella is an introduced species that specializes on Euonymus and could potentially compete with Y. multipunctella. To date, Y. cagnagella is only known to feed on introduced ornamental Euonymus and has not shifted to native species.

Photo Gallery for Yponomeuta multipunctella - American Ermine Moth		Only immatures are shown.
	Recorded by: Jim Petranka on 2024-05-22 Madison Co. Comment: Two pupae were in a partially folded leaf of Witch Hazel, about 4 feet above the ground. They presumably fed on Euonymus and moved to a pupation site on Witch Hazel. An adult was reared and emerged on May 30, 2024 (see companion photo).	Recorded by: David George, Stephen Dunn, Becky Watkins on 2024-04-13 Orange Co. Comment:
	Recorded by: Jim Petranka on 2023-05-15 Madison Co. Comment: A larva spinning a thin cocoon within a folded Viburnum leaf.	Recorded by: Jim Petranka on 2023-05-15 Madison Co. Comment: Larvae that were beginning to pupate were in folded leaves of Viburnum acerifolium on May 15. An adult was reared and emerged on May 24. The last-instar larvae apparently dispersed from a nearby Euonymus americanus bush that was a few feet away and pupated on the Viburnum. There was one larva in each leaf fold.
	Recorded by: Jim Petranka on 2023-05-15 Madison Co. Comment: Larvae that were beginning to pupate were in folded leaves of Viburnum acerifolium on May 15. An adult was reared and emerged on May 24. The last-instar larvae apparently dispersed from a nearby Euonymus americanus bush that was a few feet away and pupated on the Viburnum. There was one larva in each leaf fold.	Recorded by: David George, Becky Watkins on 2023-04-19 Durham Co. Comment:
	Recorded by: David George, Becky Watkins on 2023-04-16 Orange Co. Comment:	Recorded by: David George on 2023-04-11 Durham Co. Comment:
	Recorded by: David George on 2023-04-11 Durham Co. Comment:	Recorded by: Jim Petranka on 2022-05-20 Madison Co. Comment: A communal nest with around 30 pupae. The three oak leaves that are shown were folded together and bound with silk to form a nest. The leaves were unfolded to reveal the pupae inside.
	Recorded by: Jim Petranka on 2022-05-20 Madison Co. Comment: A communal nest with around 30 pupae. The three oak leaves that are shown were folded together and bound with silk to form a nest. The leaves were unfolded to reveal the pupae inside.	Recorded by: Jim Petranka on 2022-05-20 Madison Co. Comment: A view of eight pupae and a caterpillar that were in a communal nest. Note the very loosely woven cocoons that surround the pupae.
	Recorded by: Jim Petranka on 2022-05-18 Madison Co. Comment: Larvae were pupating beneath folded leaves of Packera aurea that were in close proximity to a Euonymus americanus shrub. They apparently drop to the ground and pupate communally in groups of 2-4 larvae in a silken nest.	Recorded by: Jim Petranka on 2022-05-18 Madison Co. Comment: Larvae were pupating beneath folded leaves of Packera aurea that were in close proximity to a Euonymus americanus shrub. They apparently drop to the ground and pupate communally in groups of 2-4 larvae in a silken nest.
	Recorded by: Jim Petranka on 2022-05-18 Madison Co. Comment: As seen here, larvae were pupating beneath folded leaves of Packera aurea that were in close proximity to a Euonymus americanus shrub. Leaves typically had 2-4 pupae in each silken nest and spun very thin whitish cocoons.	Recorded by: Jim Petranka on 2022-05-12 Madison Co. Comment: Larvae have defoliated most of the Euonymus americanus at this site.
	Recorded by: Jim Petranka and Becky Elkin on 2019-05-01 Madison Co. Comment: A communal web on American Strawberry-bush.	Recorded by: Jim Petranka and Becky Elkin on 2019-05-01 Madison Co. Comment: A communal web with early to mid-instar larvae.
	Recorded by: Jim Petranka and Becky Elkin on 2019-05-01 Madison Co. Comment:

Yponomeuta multipunctella Clemens, 1860 - American Ermine Moth

Photo Gallery for Yponomeuta multipunctella - American Ermine Moth

Only immatures are shown.