Moths of North Carolina
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Common Name:
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View PDFGracillariidae Members:
Marmara Members:
3 NC Records

Marmara fraxinicola Braun, 1922 - No Common Name

No image for this species.
Superfamily: Gracillarioidea Family: GracillariidaeSubfamily: MarmarinaeP3 Number: 330237.00 MONA Number: 709.00
Comments: The genus Marmara contains about 20 described species from North America and numerous undescribed species. Most species are monophagous, and the mines have been found on over 80 North American plant genera in 40 families (Eiseman et al., 2017). This suggests that there are dozens of undescribed species in the US.
Species Status: This is one of many ash specialists that are of conservation concern due to the destruction of ash trees by the Emerald Ash Borer.
Field Guide Descriptions: Online Photographs: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIFTechnical Description, Adults: Braun, 1922.Technical Description, Immature Stages: Braun, 1922; Fitzgerald and Simeone, 1971; Fitzgerald, 1973; Eiseman, 2019.                                                                                 
Adult Markings: The following is based on the description by Braun (1922). The maxillary palp is white inwardly and black outwardly. The labial palp is white, except for the black outer side of the second segment and a black spot near the tip of the third segment. The antenna is white and the pecten black. The head, thorax and ground color of the forewings are shining white. At the extreme base of the costa there is a small brown spot that is outwardly margined with dark brown scales. Immediately following it, and connected with it by minute brown dusting, is a large brown blotch that extends to near the mid-point of the wing. Near the middle of wing there is a posteriorly angulated fascia that is broad and brown. Following this at two-thirds, there is an oblique brown fascia that begins at the costa and forks about midway. The inner fork continues to the dorsum, while the outer fork curves to the dorsum at the tornus. Between the forked fascia and the apex there is an oblique and slightly curved brown fascia that extends to the fringe. There is a minute brown apical spot, and two oblique brown lines that run into the white cilia on either side of the apex. The cilia has a brown line that runs through the base. The hindwing and cilia are dark brown. The front and middle legs are white, with the femora brown. The lower portions have banding or spotting on the tarsi. The hind leg has oblique brown streaks.
Wingspan: 8.5 mm (Braun, 1922).
Immatures and Development: The larvae mine the stems and branches of ash trees. Larvae begin mining in the new growth in the spring or summer and continue through the year. They then overwinter and finish mining with the spring warm-up. Pupation takes place shortly thereafter in an elevated bark flap at the end of the mine (Braun, 1922; Fitzgerald and Simeone, 1971; Fitzgerald, 1973). The eggs are laid on stems or branches that are 0.6–20 cm in diameter. The mine runs along the length of the stem, with liquid frass deposited in a continuous, dark, central line along the floor of the mine. Completed mines are 55–95 cm long, about 0.7 mm wide at the origin and up to 7.5 mm wide at the end (Eiseman, 2019).
Larvae ID Requirements: Identifiable from good quality photos, especially where associated with known host plants.
Distribution in North Carolina
Distribution: Marmara fraxinicola is found in eastern North America, but the range is poorly defined because of the scarcity of records. Adults or mines have been found in Ontario, Minnesota, Ohio, Vermont, Massachusetts, Connecticut, New York, Pennsylvania, North Carolina and Texas. As of 2020, our only records are based on Tracy Feldman's recent discovery of stem mines in Durham Co. An adult record from Buncombe Co. (iNaturalist) may be this species, but has not been confirmed.
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: Local populations are univoltine and the adults are active following the spring warm-up, typically between May through July.
Habitats and Life History
Habitats: Local populations are dependent on ash trees for successful reproduction. These are found in a variety of hardwood and mixed-hardwood forests that occur in floodplains and bottomlands, as well as on more mesic to drier slopes.
Larval Host Plants: The only known hosts are White Ash (Fraxinus americana) and Green Ash (F. pennsylvanica), but other ashes may be used (Braun, 1922; Fitzgerald and Simeone, 1971; Fitzgerald, 1973; Eiseman, 2019).
Observation Methods: The adults appear to rarely visit lights and many records are based on the stem mines. We encourage naturalists to search for stem mines on ashes to document local populations that occur within the state.
See also Habitat Account for General Ash Forests
Status in North Carolina
Natural Heritage Program Status: [W3]
Natural Heritage Program Ranks: GNR S1S2
State Protection:
Comments: As of 2020, this species is only known in North Carolina from a couple of sites in Durham, but probably still occurs in other regions of the state. Marmara fraxinicola has a High Endangerment Risk due to the widespread destruction of ashes by the Emerald Ash Borer (Wagner and Todd, 2016). The threat status alone merits a high conservation concern both within the state and globally.