Moths of North Carolina
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View PDFNoctuidae Members: 40 NC Records

Eudryas unio (Hübner, [1831]) - Pearly Wood-nymph Moth

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Superfamily: Noctuoidea Family: NoctuidaeSubfamily: AgaristinaeP3 Number: 931964.00 MONA Number: 9299.00
Comments: An American genus with one species named from California and two from Georgia. The latter two species also occur in North Carolina. As Forbes (1954) points out this is a genus somewhat intermediate between Acronyctines and Agaristids. It is nocturnal, most Agaristids are diurnal, and the tympanum lacks the enlarged bulla characteristic of Agaristids. The adult and larval patterns are clearly Agaristid.
Species Status: No specimens from North Carolina or the southeast have been barcoded to date. Those from Canada and New England have been and seem to represent two species with the second one barcoding with the California species! It is as if the California species, which has the same basic pattern, has a maculation in the northeastern US and Canada which is confusingly similar to that of E. unio. Our populations need to be barcoded if only to see which of the two northern clusters they represent.
Field Guide Descriptions: Covell (1984); Beadle and Leckie (2012)Online Photographs: MPG, BugGuide, BOLDTechnical Description, Adults: Forbes (1954)Technical Description, Immature Stages: Forbes (1954); Wagner et al., (2011)                                                                                 
Adult Markings: A medium-sized, strikingly marked Noctuid. Maculation very unlike anything else in our fauna except its congener, E. grata. Both have mostly white forewings edged in purple and orange hindwings. The greenish postmedian line distinguishes the two, inwardly almost serrate in this species but smooth in E. grata which is also a much larger species. Sexes are similar.
Wingspan: 30-35 mm (Forbes, 1954)
Adult Structural Features: The male genitalia are rather typical except the aedeagus which is highly modified. The female genitalia are also strange with the ovipositor lobes enlarged and highly sclerotized but the bursae are much reduced and thread-like. Both male and female genitalia are easy to separate from those of E. grata. The modified ovipositors may reflect a peculiar method of placing eggs on the foodplants.
Structural photos
Adult ID Requirements: Identifiable from good quality photos of unworn specimens.
Immatures and Development: The caterpillar is similar to that of E. grata but the black encircling bands are broader. It is certainly worth of additional study of the behavior and palatability of both larvae and adults.
Larvae ID Requirements: Identifiable from good quality photos, especially where associated with known host plants.
Distribution in North Carolina
Distribution: All of our records come from the Piedmont and Coastal Plain
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: Apparently two broods in the Coastal Plain but too few observations elsewhere to know the brood status.
Habitats and Life History
Habitats: North Carolina records come almost entirely from open marshes and pond and lake shorelines
Larval Host Plants: Reported from a number of plants (Wagner et al, 2011) but apparently most common on Ludwigia, Lythrum and Decodon. Literature reports of caterpillars on evening primrose, gaura, hibiscus, grape and willow herb need to be confirmed and the prefererred foodplants in North Carolina should be documented
Observation Methods: Adults come to light but probably do not visit flowers or come to bait.
See also Habitat Account for General Wet Meadows
Status in North Carolina
Natural Heritage Program Status:
Natural Heritage Program Ranks: G5 [S4]
State Protection: Has no legal protection, although permits are required to collect it on state parks and other public lands.
Comments: This species appears to be somewhat uncommon but is recorded in small numbers in most examples of its habitat that have been sampled. Although a habitat specialist, it occurs widely over the state and at least some of its habitats are fairly common. This species, consequently, appears to be secure within the state.

 Photo Gallery for Eudryas unio - Pearly Wood-nymph Moth

Photos: 8

Recorded by: j.wyche on 2017-09-04
Gates Co.
Recorded by: Alicia Jackson on 2017-08-10
Tyrrell Co.
Recorded by: F. Williams, S. Williams on 2017-05-24
Gates Co.
Recorded by: Tracy S. Feldman on 2016-07-26
Scotland Co.
Recorded by: Tracy S. Feldman on 2016-07-26
Scotland Co.
Recorded by: Tracy S. Feldman on 2016-07-26
Scotland Co.
Recorded by: Robert Gilson on 2016-05-12
Mecklenburg Co.
Recorded by: Paul Scharf on 2013-09-11
Warren Co.