Moths of North Carolina
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Coptodisca Members:
2 NC Records

Coptodisca juglandiella (Chambers, 1874) - No Common Name


Taxonomy
Family: HeliozelidaeP3 Number: 210089.00 MONA Number: 248.00
Comments: This New World genus includes 18 described North American species of small leaf-mining moths, as well as several undescribed species. When mature, the larva cuts a disc of tissue out of the leaf and uses it to form a cocoon. All known species of Coptodisca feed on woody plants, and most are restricted to a single plant genus.
Identification
Field Guide Descriptions: Online Photographs: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIF, BOLD                                                                                 
Adult Markings: This is one of several native Coptodisca that are essentially identical in appearance and are best identified by rearing and knowledge of the host plants. All have a forewing that is silvery to leaden gray on the basal half and more golden colored on the apical half. The most conspicuous markings are two opposing white triangles with black margins at two thirds the length of the wing, along with a black apical patch.

The following detailed description of C. splendoriferella (see species account) is also applicable to C. juglandiella since the two are indistinguishable based on external markings. The head is bronzy, while the antenna is fuscous with a golden tinge. The forewing in leaden gray from the base to the middle, with a shiny luster. The ground color from the middle to the wing tip is golden. There is a broad, nearly straight, metallic, silvery streak at about two-thirds that extends from the costa to the middle of the wing. The streak is widest at the costa and is margined by converging black lines on both sides. Nearly opposite the costal streak is a matching dorsal streak of the same hue that also has converging dark margins. Beyond this there is a dark brown blotch that adjoin the streak, then the dorsal fringe with a blackish basal line. Beyond the large triangular costal streak is a shorter, blackish brown line in the costo-apical cilia that runs nearly perpendicular to the costa. At the wing tip is a conspicuous black, often triangular-shaped, apical spot, with a few metallic, silvery scales in its center. It is bordered by silvery scales of the cilia above and below it. A conspicuous straight black streak extends from the apical spot to the apex of the cilia. The cilia are light gray to light yellowish brown, and the hindwing is leaden gray.

Coptodisca juglandiella can be distinguished from C. lucifluella by the absence of the dark suffusion of the forewing basally of the triangular spot. Posteriorly of the spot there is usually a small area with darker suffusion (Bernardo et al., 2015).
Adult ID Requirements: Identifiable only by close inspection of structural features or by DNA analysis.
Immatures and Development: The larvae produce very small mines on walnuts. The mine starts at a midvein or lateral vein and rapidly widens to form a broadly funniform or oval blotch. Frass is typically packed into the younger half of the mine. When mature, the larva cuts an oval disc of tissue out of the leaf and uses it to form a pupal case.
Larvae ID Requirements: Identifiable from good quality photos, especially where associated with known host plants.
Distribution in North Carolina
Distribution: Coptodisca juglandiella is native to eastern North America where it is found primarily in a zone extending from Massachusetts, New York, and Pennsylvania westward through extreme southern Canada to Ohio and Wisconsin. It was recently found in North Carolina in the eastern Piedmont where it may represent a southern disjunct from the primary range to the north.
County Map: Clicking on a county returns the records for the species in that county.
Flight Dates:
 High Mountains (HM) ‚Č• 4,000 ft.
 Low Mountains (LM) < 4,000 ft.
 Piedmont (Pd)
 Coastal Plain (CP)

Click on graph to enlarge
Flight Comments: Local populations appear to have at least two generations per year in Illinois where occupied leaf mines have been found in June and September (Microleps.org).
Habitats and Life History
Habitats: Local populations are found in association with Black Walnut. This species is most commonly found along stream banks, in alluvial floodplains, and near the bases of rich forested slopes with circumneutral soils.
Larval Host Plants: Black Walnut (Juglans nigra) is the only known host for North America populations. - View
Observation Methods: The adults are indistinguishable from several other Coptodisca species based on external morphology and local populations are best documented by finding the mines on walnuts. Coptodisca lucifluella is a species that is native to North America, but has been introduced in Europe where it sometimes uses both introduced and native walnuts. Populations in the eastern US are only known to use native hickories and mines found on Black Walnut are assumed to be those of Coptodisca juglandiella.
Wikipedia
See also Habitat Account for Rich Wet-Mesic Hardwood Forests
Status in North Carolina
Natural Heritage Program Status:
Natural Heritage Program Ranks: GNR S1S3
State Protection:
Comments: This species is uncommon in North Carolina where it appears to be at the southern limit of its range.

 Photo Gallery for Coptodisca juglandiella - No Common Name

Photos: 2

Recorded by: Dean Furbish on 2022-09-22
Wake Co.
Comment: Leaf mines in Black Walnut.
Recorded by: Dean Furbish on 2022-09-22
Wake Co.
Comment: Leaf mines in Black Walnut.