Moths of North Carolina
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Eucosma Members:
8 NC Records

Eucosma sombreana Kearfott, 1905 - No Common Name


Taxonomy
Superfamily: Tortricoidea Family: TortricidaeSubfamily: OlethreutinaeTribe: EucosminiP3 Number: 620752.00 MONA Number: 3127.00
Identification
Field Guide Descriptions: Online Photographs: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIF, BOLDTechnical Description, Adults: Kearfott (1905a); Wright and Gilligan (2015)                                                                                 
Adult Markings: The following is based on part on the descriptions by Kearfott (1905a) and Wright and Gilligan (2015). The head, palps, and thorax are brown and usually heavily dusted with gray to tan specks. The forewing ground varies from reddish brown to brown and is also heavily dusted on the inner half with gray to tan specks. Faciae on the wing are poorly represented and consists of two obscure darker bands. One is an outwardly oblique sub-basal band that extends obliquely from the inner margin at about one-third and terminates before reaching the subcostal area. The second is a broad median band that begins on the costa and extends to the anal angle. A lighter interfacial area separates the two. The ocellus is poorly developed, but usually discernable. The apical half of the costa has several pale to golden brown striations, with the most prominent extending from the costa to the anal angle along the posterior margin of the dark median fascia. A second one extends from the costa to near the middle of the termen. The termen and base of the fringe have a salt-and-pepper patterning of brown and pale scaling, and the hindwing is smoky brown with a paler fringe.
Forewing Length: 7.9-12.4 mm; mean = 9.9 mm (Wright and Gilligan, 2015)
Adult Structural Features: Wright and Gilligan (2015) have illustrations of the male and female genitalia. The authors note that the male genitalia are distinctive and unlikely to be confused with those of any other North American Eucosma. The costal margin of the valva is nearly straight, and the ventral emargination is deep and U-shaped. The ventral margin of the neck is deeply scooped-out, and the ventral lobe of the cucullus is well developed, with three spiniform setae on the broad semicircular margin of the anal angle.
Adult ID Requirements: Identifiable from good quality photos of unworn specimens.
Immatures and Development: The larvae have been reported to feed on the roots and root stalks -- and presumably the tubers -- of sunflowers (Heinrich 1923; MacKay, 1959; Putman, 1942). However, details of the larval life history have not been reported. Putman (1942) found early instar larvae feeding in flowers but was uncertain if they were those of E. sombreana.
Distribution in North Carolina
Distribution: Eucosma sombreana is restricted to eastern North America with the range extending from Maine southward to northern Florida, Alabama, and Mississippi, and westward to Arkansas, eastern Oklahoma, Eastern Nebraska, Iowa, and Minnesota. It occurs in Canada in Ontario and Manitoba. As of 2022, we have records from three sites in the Blue Ridge and western 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
Flight Comments: The adults fly from June through October, with peak activity from July through September. As of 2022, our records extend from mid-July through early August.
Habitats and Life History
Habitats: Local populations are generally found in open or partially shaded habitats that support sunflowers, and are often common in prairies, old fields, roadways, and similar habitats.
Larval Host Plants: The known hosts are sunflowers (Helianthus spp.), including Giant Sunflower (H. giganteus), Jerusalem Artichoke (H. tuberosus), and Thinleaf Sunflower (H. decapitalus; Wright and Gilligan, 2015). - View
Observation Methods: The adults are attracted to lights.
Wikipedia
Status in North Carolina
Natural Heritage Program Status:
Natural Heritage Program Ranks: GNR [S2-S3]
State Protection: Has no legal protection, although permits are required to collect it on state parks and other public lands.
Comments: This species is seemingly uncommon in the state and restricted to the western counties.

 Photo Gallery for Eucosma sombreana - No common name

Photos: 9

Recorded by: David George, Stephen Dunn, Jeff Niznik on 2023-07-31
Macon Co.
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Recorded by: David George, Stephen Dunn, Jeff Niznik, Rich Teper, Becky Watkins on 2023-07-30
Swain Co.
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Recorded by: David George, Stephen Dunn, Jeff Niznik, Rich Teper, Becky Watkins on 2023-07-29
Swain Co.
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Recorded by: Jim Petranka and Becky Elkin on 2019-08-06
Madison Co.
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Recorded by: Jim Petranka and Becky Elkin on 2019-08-06
Madison Co.
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Recorded by: Jim Petranka on 2019-07-16
Madison Co.
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Recorded by: Jim Petranka on 2019-07-16
Madison Co.
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Recorded by: Jim Petranka and Becky Elkin on 2018-07-23
Madison Co.
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Recorded by: Jim Petranka and Becky Elkin on 2018-07-23
Madison Co.
Comment: Determined by J.B. Sullivan based on dissection.