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).
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.
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.
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.
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.
Minimizing lighting to maintain dark sky conditions would be beneficial.
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.
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.
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.
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).
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).
The best time to see this species is during its flight season, in June and July.
The time of year you would expect to find Dune Sympistis present and reproducing in New York.
Sympistis riparia (Morrison, 1875)
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. 2023. 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)
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. 2023. Online Conservation Guide for Sympistis riparia. Available from: https://guides.nynhp.org/dune-sympistis/. Accessed May 29, 2023.