Moths of North Carolina
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Elophila Members:
31 NC Records

Elophila gyralis (Hulst, 1886) - Waterlily Borer Moth


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Taxonomy
Superfamily: Pyraloidea Family: CrambidaeSubfamily: AcentropinaeTribe: NymphuliniP3 Number: 800727.00 MONA Number: 4751.00
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.
Identification
Field Guide Descriptions: Covell (1984; as Munroessa gyralis); Beadle and Leckie (2012)Online Photographs: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIF, BOLDTechnical Description, Adults: Munroe (1972)Technical Description, Immature Stages: McGaha (1954); Munroe (1972)                                                                                 
Adult Markings: Elophila gyralis exhibits pronounced sexual dimorphism, with the males rather boldly patterned and the females drab. The ground color of the male’s forewing varies from light brown or grayish to various shade of fuscous. The base has a wavy white antemedial line at around one-fifth that is heavily edged anteriorly with fuscous shading. The median area has a prominent dark, irregular, oval mark along the inner margin that is outlined in white. A small white spot is typically present on the costal end that is surrounded by relatively dark shading. Opposite this, and extending more posteriorly on the costal half of the wing, are three dark marks with white margins that are often joined to form a wavy loop. These include a small triangular mark in the median area of the costa, a small, subcostal, crescent-shaped mark behind this, and a short, oblique black dash in the subapical region of the costa. The final mark is a wavy, white, subterminal line with fuscous edging and teeth-like projections inwardly. The fringe is light brown or gray with darker checkering near the base. The hindwing is paler than the forewing and varies from whitish buff to medium buff. The medial area is often paler, though not contrastingly so. It is outlined by diffuse gray or fuscous lines, but not by sharp black ones as seen in some Elophila species (Munroe, 1972).

The females have relatively longer wings and have the maculation inconspicuous or obsolete due to a heavy overlap of orange-buff to brownish fuscous ground color. There are usually faint traces of the darker antemedial and postmedial lines. The hind wings are much paler than the males and range from whitish buff to grayish or yellowish buff. The medial area is somewhat paler in some specimens, and there are generally more or less distinct traces of sinuate fuscous antemedial and postmedial lines (Munroe, 1972).
Forewing Length: 8-12 mm for males and 11-14 mm for females (Munroe, 1972).
Adult ID Requirements: Identifiable from good quality photos of unworn specimens.
Immatures and Development: The larvae are easily confused with those of closely related forms and Munroe (1972) noted that the life history studies by McGaha (1952, 1954) in Michigan appear to be the only reliable sources of information. The following is based on these studies as summarized by Munroe (1972).

The elliptical eggs are laid in masses of about 25-35 in the water and immediately sink to the bottom. The larvae hatch in about 12 days and begin feeding on the lower epidermis of the leaves of the hosts, which are generally white water-lilies (Nymphaea sp.). The larvae first feed on the lower leaf surfaces of the lily pads and skeletonize the epidermal tissue. They later feed from a mobile shelter that is made by cutting a patch of leaf from the edge of the leaf, or rarely from the central part of the leaf. The feeding larvae slowly move over the course of 10-14 days to the petiole. They then bore into the top of the petiole and use the petiole tissue as food. After tunneling about 2-3 cm deep, they reverse direction and rest head up at the burrow entrance where they feed at night or on cloudy days on the leaf tissue. During this time the larvae may remain covered by the patch of leaf that it brought with it, but this is often detached by wave action. The last-instar lines the cavity in the petiole with silk and caps it with coarse silk to form a pupation chamber. The plant responds to injury of the petiole by making a gall-like swelling around the site of the excavation. The adult emerges after removing the silken cap. Pupal chambers are occasionally excavated 5-8 cm down the stem by larvae that have entered through the side. Some larvae may also occasionally pupate in sealed, air-filled chambers that are made by attaching leaf patches to the underside of the lily pad. The larvae lack gills and have an elongate prognathous head. Populations in Michigan are univoltine, with the half-grown larvae overwintering, then resuming growth with the spring warm-up.
Distribution in North Carolina
Distribution: Elophila gyralis is broadly distributed across the eastern US and adjoining areas of southern Canada from Manitoba to Nova Scotia. In the US the range extends from Maine and other New England states westward through the Great Lakes region to Minnesota, and southward to eastern Texas, southern Louisiana, southern Mississippi, southern Alabama, southern Georgia, and southern Florida. As of 2023 we have scattered records from all three physiographic provinces, with most from the Sandhills 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 have been observed year-round in Florida and during all but the coldest months of the year in other southern populations. Those in the northern regions of the range mostly fly from May through October. As of 2023, our records range from mid-April through early October.
Habitats and Life History
Habitats: Populations are strongly dependent on water-lilies for successful reproduction and typically are found in the immediate vicinity of permanent freshwater habitats that support these.
Larval Host Plants: This species appears to specialize on water-lilies (Nymphaea spp.), with Fragrant Water-lily (N. odorata being an important host (Forbes, 1910; McGaha, 1952, 1954; Munroe, 1972). - View
Observation Methods: The adults are attracted to lights and the larvae and their cases can be found on water-lily pads.
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 gyralis - Waterlily Borer Moth

Photos: 22

Recorded by: Terrell Tucker on 2023-09-14
Moore Co.
Comment: 		Recorded by: Terrell Tucker on 2023-09-14
Moore Co.
Comment:
Recorded by: Andrew W. Jones on 2023-09-12
Polk Co.
Comment: 		Recorded by: John Petranka, David George on 2023-08-05
Orange Co.
Comment:
Recorded by: Jeff Niznik on 2023-06-18
New Hanover Co.
Comment: 		Recorded by: David George, Jeff Niznik on 2023-06-11
Chatham Co.
Comment:
Recorded by: John Petranka on 2022-09-26
Orange Co.
Comment: 		Recorded by: John Petranka on 2022-09-04
Orange Co.
Comment:
Recorded by: tom ward on 2022-09-04
Buncombe Co.
Comment: 		Recorded by: David George, L. M. Carlson on 2022-07-02
Chatham Co.
Comment:
Recorded by: David George, L. M. Carlson on 2022-07-01
Chatham Co.
Comment: 		Recorded by: Jim Petranka and Bo Sullivan on 2022-05-30
Moore Co.
Comment:
Recorded by: Jim Petranka and Bo Sullivan on 2022-05-30
Moore Co.
Comment: 		Recorded by: Gary Maness on 2020-05-17
Guilford Co.
Comment:
Recorded by: Gary Maness on 2019-08-11
Guilford Co.
Comment: 		Recorded by: Gary Maness on 2019-08-11
Guilford Co.
Comment:
Recorded by: Darryl Willis on 2017-09-19
Cabarrus Co.
Comment: 		Recorded by: Darryl Willis on 2017-09-14
Cabarrus Co.
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Recorded by: Darryl Willis on 2017-05-28
Cabarrus Co.
Comment: 		Recorded by: Stephen Hall on 2017-05-02
Orange Co.
Comment: Male
Recorded by: Kyle Kittelberger on 2015-09-09
Rockingham Co.
Comment: Female		Recorded by: Doug Blatny / Jackie Nelson on 2014-09-05
Ashe Co.
Comment: