Moths of North Carolina
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View PDFNepticulidae Members:
Ectoedemia Members:
1 NC Records

Ectoedemia similella (Braun, 1917) - Broken-banded Ectoedemia

Ectoedemia similella
Taxonomy
Superfamily: Nepticuloidea Family: NepticulidaeP3 Number: 16a0088 MONA Number: 45.00
Comments: This genus includes 15 Nearctic species of very small leaf-mining moths (Van Nieukerken et al. 2016).
Species Status: Wilkinson and Newton (1981) divided the North American Ectoedemia into four species groups based primarily on genitalic differences. The platanella group consists of four species (E. clemensella; E. platanella; Ectoedemia similella; E. virgulae) that have similar traits, such as the presence of multi-branched setae on the inner sides of the valves.
Identification
Field Guide Descriptions: Online Resources: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIF, BOLDTechnical Description, Adults: Wilkinson and Newton, 1981Technical Description, Immature Stages: Braun, 1917.                                                                                 
Adult Markings: The following description of the adults is based on Braun (1917) and Wilkinson and Newton (1981). The tuft on the front of the head is orange ochreous, while the vertex is paler. The eye-cap is silvery white, and occasionally tinged with ocher, and the antenna is dark brown. The thorax and forewing are dark brown to deep bluish black. The extreme bases of the scales on the forewing are more or less iridescent blue, especially in the apical half of the wing. At the middle of the forewing there is an oblique narrow costal streak that is shining white, but not silvery. The costal streak usually meets or nearly meets the apex of a shorter and broader dorsal streak to form an oblique median fascia. The extent to which a fascia is present varies among individuals, and may simply consists of two white streaks with a gap between them. The tips of the last row of scales around the apex are dark, and form a dark line in the otherwise white cilia. The hindwing is gray. The male hindwing has a narrow chitinous plate from the base to one-third of the costa, with a long yellowish costal hair-pencil lying along it. The legs and abdomen are fuscous above, silvery beneath, with a yellow anal tuft in the male.

Wilkinson and Newton (1981) observed that Florida specimens deviate from populations elsewhere in the range. Florida specimens typically have a darker ground color that is dusted with gray reflections, and a median fascia that is often incomplete, with the marginal streaks sometimes greatly reduced in size. In addition, the extreme apex of the fringe is creamy white, which gives the impression of an apical spot. Braun (1917) noted that females of this species can only be distinguished from those of N. platanella by the less shining costal and dorsal spots, while males differ in the yellowish costal hair-pencil of the hindwing. Wilkinson and Newton (1981) reported that E. similella is more often smaller and more iridescent than E. platanella and E. clemensella, and differs in the irrorate nature of the forewing ground color. This species has the lance-shaped chitinous plate on the male hindwing that is absent in E. clemensella. Specimens are best identified via rearing, since the host species are different.
Wingspan: 4.6—5.6 mm for males; 4.2—6.0 mm for females (Wilkinson and Newton, 1981).
Adult Structural Features: Wilkinson and Newton (1981) found that the male genitalia are very similar to those of E. platanella, except that the saccus is markedly bilobed, with each lobe being as long as broad at the base. The valves are rounded distally with a small apical style, and the setae of the dorsal surface are broad and fan-like. The aedeagus is markedly shorter than the capsule, and the anellus comprising a pair of blunted, digitate processes. The female genitalia also resemble the genitalia of E. platanella, except that the sclerotized double ring has the inner margin weakly serrate, and the lobe of the ductus has small triple spicules. The signa is small in relation to the bursa copulatrix and unequal in size. In general, the saccus of E. similella is more markedly bilobed than in E. platanella and E. virgulae, but less than in E. clemensella. The broad, fan-like scales of the valves differ from those of E. platanella, E. clemensella and E. virgulae. The female genitalia resemble those of the other members of the platanella group in most respects. The only consistent differences are the unequal size of the signa, and the very small spicules of the lobe.
Immatures and Development: Females deposit their eggs on the upper surfaces of oak leaves. The hatchling initial produces a mine that is very narrow and completely filled with frass. The mine typically bends several times in close S-shaped curves. The larva next mines just above the lower epidermis and forms a lower-surface blotch that is scarcely visible above, except for occasional spots toward the edges of the blotch where the tissue is more fully consumed. Finally, a conspicuous large blotch is formed that is transparent and whitish, with frass accumulating toward the beginning of the blotch. The larva is pale green and emerges from a slit in the blotch to spin an external, light brown cocoon.
Larvae ID Requirements: Identifiable from good quality photos, especially where associated with known host plants.
Distribution in North Carolina
Distribution: Ectoedemia similella is found in Ontario, Canada and throughout much of the eastern US. Populations occur from Ohio eastward to Connecticut and New Jersey. From there, the species ranges southward to Alabama and Florida and westward to as far as Arkansas and Oklahoma. As of 2020, we only have a record from Scotland County.
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)

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