Dune Sympistis

Sympistis riparia (Morrison, 1875)

Oncocnemis riparia
Jim Vargo

Insecta (Insects)
Noctuidae (Owlet Moths)
State Protection
Not Listed
Not listed or protected by New York State.
Federal Protection
Not Listed
State Conservation Status Rank
Unrankable - Currently unrankable due to lack of information or due to substantially conflicting information about status or trends.
Global Conservation Status Rank
Apparently Secure globally - Uncommon in the world but not rare; usually widespread, but may be rare in some parts of its range; possibly some cause for long-term concern due to declines or other factors.


Did you know?

Only a few species in the genus "Oncocnemus" occur in eastern North America, including this species. Many more species in the genus occur in the American Southwest (Wagner et al. 2008).

State Ranking Justification

One population is documented in Suffolk County. In New York State, the species is likely restricted to Long Island and nearby offshore islands, since it seems to be a Great Lakes and Atlantic Coast species (Wagner et al. 2008). Additional surveys are needed to better understand its status and distribution in New York State.

Short-term Trends

The short-term trend for this species in New York State is unknown. Twenty-nine moths were captured in blacklight traps on Robins Island in 1997. The site has not been surveyed since.

Long-term Trends

The long-term trend for this species is unknown. Historically, the species was reported from Long Island (Forbes 1954). Recently, it was documented in Suffolk County in 1997.

Conservation and Management


The threats to this species in New York State are uncertain. Elimination and fragmentation of habitat by commercial and residential development are probably the most significant threats.

Conservation Strategies and Management Practices

Minimizing lighting to maintain dark sky conditions would be beneficial.

Research Needs

Research is needed to learn more about the life history of the species and determine the larval foodplant.



This species might inhabit a variety of habitats, but it is thought to mostly inhabit dunes.

Associated Ecological Communities

  • Maritime beach* (guide)
    A community with extremely sparse vegetation that occurs on unstable sand, gravel, or cobble ocean shores above mean high tide, where the shore is modified by storm waves and wind erosion.
  • Maritime bluff* (guide)
    A sparsely vegetated community that occurs on vertical exposures of unconsolidated material, such as small stone, gravel, sand, and clay, that is exposed to maritime forces, such as water, ice, or wind.
  • Maritime dunes (guide)
    A community dominated by grasses and low shrubs that occurs on active and stabilized dunes along the Atlantic coast. The composition and structure of the vegetation is variable depending on stability of the dunes, amounts of sand deposition and erosion, and distance from the ocean.
  • Maritime grassland* (guide)
    A grassland community that occurs on rolling outwash plains of the glaciated portion of the Atlantic coastal plain, near the ocean and within the influence of offshore winds and salt spray.
  • Successional old field*
    A meadow dominated by forbs and grasses that occurs on sites that have been cleared and plowed (for farming or development), and then abandoned or only occasionally mowed.

* probable association but not confirmed.


New York State Distribution

This species is documented from Long Island (Forbes 1954) and a nearby offshore island, Robins Island. It is likely restricted to Long Island and nearby offshore islands, since it is confined to the coast for much of its range.

Global Distribution

This species has been reported from the Great Lakes region and the Atlantic Coast. It has been reported from Long Island (Forbes 1954), New Jersey, Massachusetts, Indiana, Wisconsin, and Ontario (NatureServe 2010). For most of its known range, it is confined to the coast. Long Island is the southern part of its range.

Identification Comments

Identifying Characteristics

This is a mostly brown moth. The forewing is patterned with various shades of brown and white. The hind wing is paler with some dark veins and is darker at the outer edges. The wingspan is approximately 34-35 mm. Caterpillars have a stripe adjacent to or passing through the spriacles that reaches the anal plate but does not curve down along the anal proleg (Wagner et al. 2008).

Best Life Stage for Proper Identification

The adult is the best life stage for identification.


The life history of this species is unknown (Wagner et al. 2008).


The larval foodplant (the plant on which caterpillars of this species feed) is unknown. However, it is known that caterpillars in the subfamily "Oncocnemidinae", such as this species, tend to be foodplant specialists, and they often prefer to feed on flowers or fruits of low-growing plants (Wagner et al. 2008).

Best Time to See

The best time to see this species is during its flight season, in June and July.

  • Present
  • Reproducing

The time of year you would expect to find Dune Sympistis present and reproducing in New York.

Dune Sympistis Images


Dune Sympistis
Sympistis riparia (Morrison, 1875)

  • Kingdom Animalia
    • Phylum Arthropoda (Mandibulates)
      • Class Insecta (Insects)
        • Order Lepidoptera (Butterflies, Skippers, and Moths)
          • Family Noctuidae (Owlet Moths)

Additional Resources


Forbes, William T. M. 1954. Lepidoptera of New York and neighboring states part III. Cornell University Experiment Station Memoir 329.

NatureServe. 2010. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer. (Data last updated August 2010)

New York Natural Heritage Program. 2024. New York Natural Heritage Program Databases. Albany, NY.

North American Moth Photographers Group at the Mississippi Entomological Museum. No date. Mississippi State University, Mississippi. http://mothphotographersgroup.msstate.edu/MainMenu.shtml

Opler, Paul A., Kelly Lotts, and Thomas Naberhaus, coordinators. 2010. Butterflies and Moths of North America. Bozeman, MT: Big Sky Institute. <http://www.butterfliesandmoths.org/> (accessed May 2010).

Schweitzer, Dale F. 1998. Rare, potentially rare, and historic macrolepidoptera for Long Island, New York: A suggested inventory list.

Wagner, D. L., D. F. Schweitzer, J. B. Sullivan, and R. C. Reardon. 2008. Owlet Caterpillars of Eastern North America (Lepidoptera: Noctudiae)


About This Guide

This guide was authored by: Andrea Chaloux

Information for this guide was last updated on: February 9, 2012

Please cite this page as:
New York Natural Heritage Program. 2024. Online Conservation Guide for Sympistis riparia. Available from: https://guides.nynhp.org/dune-sympistis/. Accessed May 26, 2024.