Switchgrass Dart

Dichagyris acclivis (Morrison, 1875)

Dichagyris (Loxagrotis) acclivis Hugh D. McGuinness

Dichagyris (Loxagrotis) acclivis
Hugh D. McGuinness

Class
Insecta (Insects)
Family
Noctuidae (Owlet Moths)
State Protection
Not Listed
Not listed or protected by New York State.
Federal Protection
Not Listed
State Conservation Status Rank
S2S3
Imperiled or Vulnerable in New York - Very vulnerable, or vulnerable, to disappearing from New York, due to rarity or other factors; typically 6 to 80 populations or locations in New York, few individuals, restricted range, few remaining acres (or miles of stream), and/or recent and widespread declines. More information is needed to assign either S2 or S3.
Global Conservation Status Rank
G4G5
Apparently or Demonstrably Secure globally - Uncommon to common 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. More information is needed to assign either G4 or G5.
Contents
  1. Summary
  2. Conservation and Management
  3. Habitat
  4. Range
  5. Identification Comments
  6. Taxonomy
  7. Additional Resources
  8. About This Guide

Summary

Did you know?

Larvae of this species burrow underground during the day, safe from above-ground predators. The larvae are best adapted to sandy areas in which it is easy to burrow, where, as expected, this moth tends to be most abundant (Wagner et al. 2008).

State Ranking Justification

Habitat for this moth is potentially abundant. However, the moth might be restricted to the coastal plain, as it is in New Jersey. Four populations have been documented in the state on Long Island and a nearby island. Two of these were first documented in 2007. Additional surveys are needed to better understand the status and distribution of this moth in the state.

Short-term Trends

The short-term trend for this species in New York State appears to be stable. At one of four documented populations in the state, similar numbers of moths were captured in 1995 and 2000, resulting in nearly 30 adults captured over the course of the two years. Each of the other three populations were first documented in 1997 or 2007 and have not been surveyed since.

Long-term Trends

The long-term trend for this species in New York State is unknown.

Conservation and Management

Threats

Suppressing fire in naturally fire-maintained habitats and allowing habitat succession may eliminate habitat for this moth that feeds on grasses. Elimination and fragmentation of habitat by commercial and residential development are additional threats.

Conservation Strategies and Management Practices

Areas where this moth has been found need to be evaluated to avoid additional encroachment or fragmentation by development. At some locations, periodic controlled burns or other measures may be needed to restore or maintain grassland habitat where the moth occurs. Minimizing lighting to maintain dark sky conditions would also be beneficial.

Habitat

Habitat

The habitat for this species in New York State seems to be sandy, grassy areas with an abundance of switchgrass (Panicum virgatum). Larvae commonly feed on this grass in wet places such as ditches and streamsides (D. Schweitzer, personal communication).

Associated Ecological Communities

  • 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.
  • Maritime heathland (guide)
    A dwarf shrubland community that occurs on rolling outwash plains and moraine of the glaciated portion of the Atlantic coastal plain, near the ocean and within the influence of onshore winds and salt spray.
  • Sea level fen* (guide)
    A wetland that occurs at the upper edge of salt marshes but is fed primarily by acidic groundwater seeping out along the upland edge. This fresh water sometimes mixes with salt or brackish water during unusually high tides. There is a high abundance of sedges that decompose slowly and create a deep substrate of peat. This peat is underlain by deep sand or gravel. These fens usually have a high diversity of herbs but may also have scattered trees and shrubs.

* probable association but not confirmed.

Range

New York State Distribution

This moth might be restricted to the coastal plain, as it is in New Jersey. It has been documented from four sites in Suffolk County, on Long Island and a nearby island.

Global Distribution

This moth is documented from Kansas, northwestern Connecticut, and Cape Cod south to North Carolina and Texas. It seems uncommon in areas other than the northeastern part of its distribution (Wagner et al. 2008).

Best Places to See

  • Montauk County Park (Suffolk County)

Identification Comments

Identifying Characteristics

Like many other noctuids (owlet moths), this is a small, brown moth. The forewing is patterned with several shades of brown, and the hind wing is mostly white. The wingspan is approximately 32 mm. Larvae are hardy and smooth (Wagner et al. 2008).

Best Life Stage for Proper Identification

The adult is the best life stage for identification.

Behavior

Adults fly from mid July to early August. The females lay one brood of eggs each year. Larvae emerge from the eggs and become mature caterpillars in September and early October. The larvae burrow underground during the day, where they are safe from predators. They emerge at night to feed on the developing seeds of switchgrass (Panicum virgatum) (Wagner et al. 2008), usually in wet areas such as ditches and streamsides (D. Schweitzer, personal communication). Larvae spend the winter underground as prepupae, and pupation occurs in a cell underground. Prepupal larvae of some closely related species (and perhaps this species) aestivate underground for three or four months during the summer before emerging as adult moths (Wagner et al. 2008).

Diet

Larvae feed on the developing seeds of switchgrass (Panicum virgatum) (Wagner et al. 2008). It is possible that they also use other grasses (D. Schweitzer, personal communication).

Best Time to See

The best time to see this species is during its flight season, from mid July to early August.

  • Present
  • Reproducing
  • Larvae present and active

The time of year you would expect to find Switchgrass Dart present, reproducing, and larvae present and active in New York.

Switchgrass Dart Images

Taxonomy

Switchgrass Dart
Dichagyris acclivis (Morrison, 1875)

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

Synonyms

  • Richia acclivis (Morrison, 1875)

Comments on the Classification

Synonyms include Richia acclivis and Agrotis acclivis (Forbes 1954).

Additional Resources

References

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

Lafontaine, J.D. 2004. Noctuoidea: Noctuidae (part): Noctuinae (part–Agrotini). In: Hodges RW (Ed). Fascicle 27.1. The Moths of America North of Mexico. The Wedge Entomological Research Foundation, Washington, DC. 385 pp., 75 plates.

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).

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

Links

About This Guide

This guide was authored by: Andrea Chaloux

Information for this guide was last updated on: March 6, 2012

Please cite this page as:
New York Natural Heritage Program. 2023. Online Conservation Guide for Dichagyris acclivis. Available from: https://guides.nynhp.org/switchgrass-dart/. Accessed September 23, 2023.