Moths of North Carolina
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View PDFNepticulidae Members:
Stigmella Members:
5 NC Records

Stigmella juglandifoliella (Clemens, 1861) - No Common Name

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Superfamily: Nepticuloidea Family: NepticulidaeP3 Number: 160021.00 MONA Number: 95.00
Comments: Members of the genus Stigmella are a group of small leaf-mining moths that typically create linear mines, although a few species form linear-blotch or blotch mines. Newton and Wilkinson (1982) recognized 51 species in their revision on the North American fauna, and new discoveries have since raised the total to around 57 species. Almost all species are specialists and rarely use more than one genus of host plants. Host-specificity, mine characteristics, and genitalic differences are helpful in recognizing closely related forms that are externally similar.
Field Guide Descriptions: Online Photographs: MPG, BugGuide, GBIF, BOLDTechnical Description, Adults: Wilkinson and Scoble, 1979.                                                                                 
Adult Markings: The following description of the adults is based on descriptions in Wilkinson and Scoble (1979). The palps are gray and lustrous, and the antenna is purplish gray and lustrous. The eye-cap is shining white and often has brownish purple shading around the edges. The collar varies from pale ochreous to gray-purple. The tuft on the front of head and vertex is pale ochreous to bright orange-ochreous. The thorax and abdomen are dark grayish purple. The ground color of the forewing is blackish with reddish bronze and purple reflections. There is a single rather narrow, white, postmedial fascia that is shining silver. The fringe is gray and irrorate with brown. The legs are dark gray to pale ochreous. Stigmella juglandifoliella is indistinguishable from S. ostryaefoliella and S. corylifoliella based on external traits. It is best identified using genitalia, barcoding, or host plant affiliation (Wilkinson and Scoble, 1979).

Wingspan: 3.0-3.4 mm (Wilkinson and Scoble, 1979).
Adult Structural Features: The vinculum has a very large ventral plate. The saccus is very weakly bilobed, and the uncus has a pair of widely separated horns. The gnathos is sigmoid and the valves are broad with the style pointed. The transtilla lacks large triangular processes at the ends of the lateral bars. Wilkinson and Scoble (1979) noted that the male genitalia are similar to those of S. corylifoliella and S. ostryaefoliella, but can be distinguished by the overall form of the genital capsule. In particular, it can be distinguished by the large ventral plate of the vinculum, the form of the valves, the nature of the uncus, and the very sigmoid gnathos.

Adult ID Requirements: Identifiable only by close inspection of structural features or by DNA analysis.
Immatures and Development: The larvae are pale green and form narrow, whitish mines on walnut leaflets. Each mine has a narrow, black central frass line. The final instar exits the leaflet and spins a brownish-red cocoon (Eiseman, 2019). There can sometimes be two or more mines on a single leaflet.
Larvae ID Requirements: Identifiable from good quality photos, especially where associated with known host plants.
Distribution in North Carolina
Distribution: Scattered populations of S. juglandifoliella have been found in eastern North America from Wisconsin, Ohio and Ontario, eastward to Massachusetts and south and southwestward to Kentucky, Tennessee, and North Carolina. As of 2022, we have only five site records from the eastern 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: Based on mine records, the adults appear to be active during the summer months after walnuts are fully leafed-out (June-Sept.).
Habitats and Life History
Habitats: This species is dependent on our native walnuts, which are most commonly found in nutrient-rich, floodplain forests. They are less commonly found at the base of rich forested slopes with circumneutral soils.
Larval Host Plants: As the name implies, S. juglandifoliella is a specialist on walnuts. It uses both Black Walnut (Juglans nigra) and Butternut (J. cinerea). As of 2022, our North Carolina records are all from Black Walnut.
Observation Methods: The adults appear to rarely visit lights. Most records are based on leaf mines or adults that were raised from leaf mines. We recommend searching for mines during the summer months and rearing the adults.
Status in North Carolina
Natural Heritage Program Status:
Natural Heritage Program Ranks: GNR SU
State Protection:
Comments: We have only five records for North Carolina as of 2022. This species is probably more common than our limited records suggest due to the lack of focus on leafminers in the state.

 Photo Gallery for Stigmella juglandifoliella - No Common Name

Photos: 8

Recorded by: Dean Furbish on 2022-09-22
Wake Co.
Recorded by: Dean Furbish on 2022-09-22
Wake Co.
Recorded by: Jim Petranka on 2022-09-19
Buncombe Co.
Recorded by: Jim Petranka on 2022-06-16
Madison Co.
Recorded by: Jim Petranka on 2022-06-16
Madison Co.
Comment: Unoccupied mines were on Black Walnut.
Recorded by: Vin Stanton on 2021-09-27
Buncombe Co.
Recorded by: Vin Stanton on 2021-09-27
Buncombe Co.
Recorded by: Harry Wilson on 2015-07-02
Wake Co.
Comment: A view of a leaf mine of Black Walnut. Note the thin, dark frass line.