Moths of North Carolina
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7 NC Records

Choristoneura conflictana (Walker, 1863) - Large Aspen Tortrix

Choristoneura conflictana
Taxonomy
Superfamily: Tortricoidea Family: TortricidaeSubfamily: TortricinaeTribe: ArchipiniP3 Number: 51a0302 MONA Number: 3637.00
Species Status: Choristoneura conflictana is a major pest on Quaking Aspen and can cause significant defoliation of trees over hundreds of square kilometers. Populations often reach high levels for two or three years, then crash and remain low for many years before another outbreak occurs.
Identification
Field Guide Descriptions: Beadle and Leckie (2012)Online Resources: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIF, BOLDTechnical Description, Adults: Forbes (1923)                                                                                 
Adult Markings: The following description is based in part from that of Forbes (1923). The head, palps, antennae, and thorax are all dull gray to light brownish-gray. The ground of the forewing is similar and is faintly reticulated or striated with fine and somewhat diffuse darker lines. The ground is overlain with three darker, diffuse, grayish brown patches or bands. These include a basal patch that cover the basal one-fourth of the wing, a posteriorly oblique median band that extends from the middle of the costa to the inner margin, and a semi-oval costal patch before the apex. The area between the costal patch and the tornus is often filled with heavy concolorous dusting which, together with the patch, creates a diffuse triangular mark below the apex. Specimens often have an overall velvety look due to the diffuse marks that prevail on the forewing.
Wingspan: 25-35 mm (Forbes, 1923)
Adult Structural Features: Freeman (1958) and Dang (1992) has detailed descriptions and illustrations of the male genitalia.
Adult ID Requirements: Identifiable from good quality photos of unworn specimens.
Immatures and Development: The following life history account is mostly based on summaries by Cerezke (1992) and Baker (1972) for Canadian populations where Quaking Aspen is the primary host. The females that emerge in June or July lay clusters of 50-450 eggs on the upper surfaces of leaves. The first instar larvae sometimes mine the buds and also feed gregariously within webbed leaves before moving to tree trunks or other cover to find overwintering sites. After arriving, they spin cocoons and molt, then spend the winter in the second instar. The following spring, they climb the trees and mine the swelling buds and skeletonize the young leaves. Later, they roll leaves, fold individual leaves, or bind adjoining leaves together to form feeding shelters where they consume most of the leaf tissue. Pupation occurs either on the leaves, within the rolls or shelters, or in the underbrush. The larvae are initially pale yellowish-green, but become dark green or blackish as they reach the final instars. The full grown larvae are are 12 to 21 mm long. The prothoracic shield varies from reddish-brown to black, and the thoracic legs are black.

Local and regional populations occasionally have major outbreaks that can seriously defoliate trees. Many outbreaks have occurred in aspen stands in Canada, as well as in New England, New York, and Michigan. During outbreaks the larvae often feed on other tree species that are in the vicinity of the primary host.
Distribution in North Carolina
Distribution: Choristoneura conflictana is primarily found at northern latitudes or in mountainous terrain elsewhere, particularly where Quaking Aspen is found. It occurs from Alaska across a broad swath of Canada eastward to Nova Scotia and Prince Edward Island. In the US, populations occur in northern California, the central and northern Rockies, and in the eastern US from Maine westward to North Dakota and southward to Nebraska, Iowa, Illinois, Indiana, Ohio, New York, and Maryland. Isolated records exist in northern Florida and in North Carolina. As of 2023, we have only two records for the state, with one from Polk County being historical.
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: Populations are univoltine. The adults flying from May through August, with the great majority emerging in June and July. As of 2022, our two records are from May.
Habitats and Life History
Habitats: Local populations are typically associated with Quaking Aspen groves in boreal habitat. Both of our records are from residential and urban areas and might reflect introductions.
Larval Host Plants: The larvae are polyphagous and mostly feed on deciduous trees (Craighead et al., 1950; Freeman, 1958; Heppner, 2007; MacKay (1962); Prentice, 1966; Robinson et al., 2010). Quaking Aspen (Populus tremuloides) is the primary host in Canada, but many other species are used, particularly during outbreaks. The other known hosts include Box Elder (Acer negundo), alders (Alnus spp.), Downy Serviceberry (Amelanchier arborea), Yellow Birch (Betula alleghaniensis), Gray Birch (B. populifolia), Alternate-leaf Dogwood (Cornus alternifolia), hazelnuts (Corylus), American Beech (Fagus grandifolia), apples (Malus domestica), White Pine (Pinus strobus), White Poplar (Populus alba), Balsam Poplar (P. balsamifera), Eastern Cottonwood (P. deltoides), Bigtooth Aspen (P. grandidentata), Fire Cherry (Prunus pensylvanica), Choke Cherry (P. virginiana), roses (Rosa), willows (Salix), Sorbus, and Vaccinium. - View
Observation Methods: The adults are attracted to lights and the larvae are easily detected since they often cause extensive defoliation on the host plants.
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: We have only two records as of 2023 and these may reflect introductions from this boreal species.

 Photo Gallery for Choristoneura conflictana - Large Aspen Tortrix

Photos: 5

Recorded by: Darryl Willis on 2021-04-19
Cabarrus Co.
Comment: 		Recorded by: Darryl Willis on 2016-03-23
Cabarrus Co.
Comment:
Recorded by: Darryl Willis on 2016-03-08
Cabarrus Co.
Comment: 		Recorded by: Darryl Willis on 2016-03-03
Cabarrus Co.
Comment:
Recorded by: Darryl Willis on 2014-04-23
Cabarrus Co.
Comment: