Moths of North Carolina
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Elophila Members:
15 NC Records

Elophila tinealis Munroe, 1972 - Black Duckweed Moth

Elophila tinealisElophila tinealisElophila tinealis
Taxonomy
Superfamily: Pyraloidea Family: CrambidaeSubfamily: AcentropinaeTribe: NymphuliniP3 Number: 80a1312 MONA Number: 4754.00
Comments: The genus Elophila contains nearly 50 described species that occur on most continents worldwide. Nine species occur in North America – including seven in North Carolina -- and all have aquatic larvae that feed on floating and submerged plants. The larvae live in cases that are constructed from cut-out portions of leaves or leaf fragments, with pupation occurring within the case. The larvae are gill-less and appear to obtain oxygen by storing air in their cases.
Species Status: "Females of tinealis and males of obliteralis can be confused. Need to know size and sex" (Scholtens, 2017)
Identification
Field Guide Descriptions: Beadle and Leckie (2012; as Synclita tinealis)Online Resources: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIF, BOLDTechnical Description, Adults: Munroe (1972)                                                                                 
Adult Markings: Elophila tinealis is the smallest member of this genus in North Carolina (forewing length = 3-5 mm) and is more-or-less unicolorous with relatively narrow, dark-fuscous wings that lack lighter-colored markings. The following description is mostly based on the description by Munroe (1972). The frons is more rounded and the labial palps are more closely and smoothly scaled than in other species of the genus. The head, thorax, and wings are uniformly blackish fuscous above, although some individuals may have a dusting of whitish scales on the forewing that are sometimes organized as a faint, subcostal spot at around two-thirds the wing length. In general, males tend to be slightly darker than females. The forewings are smoothly rounded, and the legs are grayish fuscous and lack conspicuous marks.
Forewing Length: 3-5 mm (Munroe, 1972).
Adult Structural Features: Munroe (1972) has illustrations and descriptions of the male genitalia. He notes that the uncus is long, slender, and somewhat flattened, while the gnathos is a little shorter than the uncus and very slender and hardly expanded at the tip. The aedeagus is cylindrical and obtusely bent near the tip. It is armed with a single short, sharp, and rather thick cornutus. The median process of the male eighth abdominal sternite is sharp and is armed with three or more parallel setalike spines. The female genitalia have the ductus bursae and bursa very weakly sclerotized.
Adult ID Requirements: Identifiable from photos showing hindwings, abdomen, or other specialized views [e.g., frons, palps, antennae, undersides].
Immatures and Development: The larvae are aquatic and feed on several species of aquatic plants, particularly duckweeds. Most of our knowledge about the larval life history is based on specimens that were grown in the laboratory by Kinser and Neunzig (1981). The authors collected specimens from four sites in North Carolina where in all instances the larvae fed on duckweeds (Lemna and Spirodella). Female laid an average of 82 eggs in the lab that hatched in five days at 27 C. The eggs were placed in groups of 1-10 on the undersides of the host plants. There were five larval stages that lasted approximately 3 days each at 27 C, as was the case for the pupal stage. The larvae made silk cases that were plastered with duckweed. As they grew, they expanded the case and often cut-off the oldest portions. Pupation occurred in the final case, which often floated at the water's surface.
Distribution in North Carolina
Distribution: Elophila tinealis is found throughout the eastern US and in Ontario and Quebec. In the US the range extends from the New England states westward to Minnesota and southward to southeastern Texas, the Gulf States, and southern Florida. As of 2023, our records are restricted to the Coastal Plain and eastern 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 year-round or nearly so in the southernmost areas of the range, but mostly from May through October farther north. AS of 2023, our records are from late-May to early October.
Habitats and Life History
Habitats: The larvae are aquatic and use vegetated wetlands, including those with running water such as canals.
Larval Host Plants: The larvae likely feed on a variety of aquatic plants as is the case for most aquatic crambids. Stoops et al. (1998) reported that Water-shield (Brasenia shreberi) and duckweeds (Lemna) appeared to be important hosts. Kinser and Neunzig (1981) also found that duckweeds (Lemna; Spirodella) appeared to the most important hosts species. When presented with several other aquatic plants, the larvae fed on Azolla, Elodea and Myriophyllum moderately, while largely avoiding Potamogeton, Polygonum, and Nuphar. - View
Observation Methods: The adults are attracted to lights and larvae can be found by searching aquatic plants.
Wikipedia
See also Habitat Account for General Herbaceous Ponds
Status in North Carolina
Natural Heritage Program Status:
Natural Heritage Program Ranks: GNR S3S4
State Protection: Has no legal protection, although permits are required to collect it on state parks and other public lands.
Comments:

 Photo Gallery for Elophila tinealis - Black Duckweed Moth

Photos: 11

Recorded by: Mark Basinger on 2024-05-08
Wilson Co.
Comment: 		Recorded by: Stephen Hall on 2023-05-23
Orange Co.
Comment:
Recorded by: David George, Jeff Niznik, Rich Teper on 2023-05-21
New Hanover Co.
Comment: 		Recorded by: David George, L. M. Carlson on 2022-07-19
Chowan Co.
Comment:
Recorded by: David L. Heavner on 2021-08-18
Chatham Co.
Comment: 		Recorded by: Gary Maness on 2018-09-20
Guilford Co.
Comment:
Recorded by: Gary Maness on 2018-09-20
Guilford Co.
Comment: 		Recorded by: Darryl Willis on 2017-07-04
Cabarrus Co.
Comment:
Recorded by: Stephen Hall and Ed Corey on 2016-10-01
Bladen Co.
Comment: 		Recorded by: Darryl Willis on 2016-09-01
Cabarrus Co.
Comment:
Recorded by: T. DeSantis on 2013-07-26
Camden Co.
Comment: