Summary

Did you know?

This moth is named after Eliza Bridgham who studied and collected moths in Rhode Island. She was also the mother of entomologist and artist Joseph Bridgham. In addition, its patterning and coloration which liken it to decorative "brocade" woven fabrics.

State Ranking Justification

There are two known occurrences of Oligia bridghami in New York (in Clinton and Suffolk counties). Further inventory is needed to determine the New York distribution, trends, habitat requirements, and threats to the species in order to determine an appropriate rank. Covell (1984) called this moth uncommon, but its food plant is not known and its biology is poorly understood.

Short-term Trends

Bridgham's Brocade moth has been documented in two disjunct locations in New York since 2003. Since sightings of this species are fairly recent in the state, short-term trends are unclear.

Long-term Trends

Information on Oligia bridghami occurrences in New York prior to 2003 are lacking; therefore, long-term trends are unknown.

Conservation and Management

Threats

Known threats to maritime grasslands include habitat loss due to development and fire suppression, although the threat of development for the remaining habitat on Long Island may be low. The suppression of fires in barrens and other fire-dependent habitats could cause a degradation of habitat for this species and therefore a drop in population size. Conversely, a fire affecting an entire occurrence could eliminate all life stages that are present (Schweitzer et al. 2011).

Bridgham's Brocade moths are attracted to artificial lighting. Artificial lighting can: increase predation risk, disrupt behaviors such as feeding, flight, and reproduction, and interfere with dispersal between habitat patches. In addition, many individuals die near the light source. It is not known if the impact of artificial lighting is severe, but the impact is likely greater for small, isolated populations (Schweitzer et al. 2011).

The use of insecticides and biocontrols can also eliminate or greatly impact many non-target moth populations. Persistent use of insecticides and biocontrols could potentially eliminate local populations (Schweitzer et al. 2011).

Please refer to the NYNHP community conservation guides for maritime grassland and sandstone pavement barrens for specific information on threats and management considerations for these habitat types where Oligia brighami is known to reside in New York.

Conservation Strategies and Management Practices

Historically, fire has played a role in maintaining maritime grasslands. The entire occupied habitat for a population should not be burned in a single year. For example, in places where prescribed burning is used, refugia (unburned areas) are needed for many species to ensure that any life stage can survive a fire. Schweitzer et al. (2011) suggests waiting five years before burning a unit again to give the lepidopteran population a chance to recolonize and increase local populations to withstand another fire. It may also be beneficial to know the locations of rare lepidopterans since there's a chance of losing localized populations if there are no individuals at the area set aside as refugia (Schweitzer et al. 2011).

In addition, minimizing lighting to maintain dark sky conditions would be beneficial. When lighting is necessary, it's best to use lights that emit red or yellow light because insects are generally not attracted to those colors. However, many sodium lights, which emit yellow light, are so bright that they do attract some insects. The best lighting appears to be low pressure sodium lights which have little effect on flying insects (Schweitzer et al. 2011).

Insecticide use should be avoided when possible if rare species are present. When insecticide use cannot be avoided, careful planning along with consistent rare species monitoring, can result in successful eradication of the target species without eliminating rare species. A biocontrol alternative is Bacillus thuringiensis (Btk) for some target species, such as spongy moth. However, sensitivity to Btk varies among native species and this option should be fully researched for treatment timing and regimes and weighed with other options to have the least impact on native lepidopteran populations (Schweitzer et al. 2011).

Please refer to the NYNHP community conservation guides for maritime grassland and sandstone pavement barrens for specific information on threats and management considerations for these habitat types where Oligia brighami is known to reside in New York.

Research Needs

Further inventory is needed to define the distribution, population size, and conservation status of Bridgham's Brocade moth in New York. In addition, research is required to understand the habitat requirements and larval foodplants for this species.

Habitat

Habitat

In New York, Bridgham's Brocade moths have been found at the edges of sea level fen and martitime heathland, dunes, and grassland on Long Island. They have also been documented in a sandstone pavement barrens natural community in Clinton county dominated by jack pine and containing shrubs, mosses, lichens, and ferns (New York Natural Heritage Program 2011). Larval foodplant requirements are currently unknown; however, the larvae are believed to be generalists or feed on widely distributed plants (NatureServe 2012).

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.
• Sandstone pavement barrens (guide)
  An open canopy woodland that occurs on very shallow soils over sandstone bedrock; this community is best developed where the bedrock is nearly level, thus forming a pavement. The best developed examples are found on Potsdam Sandstone in Clinton County. Large examples often include wetlands, such as perched bogs and inland poor fens.
• 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.

Range

New York State Distribution

Oligia bridghami is known from Clinton and Suffolk counties in New York (New York Natural Heritage Program, 2011). With our current knowledge of the species, it appears to have a disjunct population in New York.

Global Distribution

Bridgham's Brocade moth is currently known from Ontario, Canada and Wisconsin, Indiana, Pennsylvania, New York, and Rhode Island in the United States.

Best Places to See

• Gadway Sandstone Pavement Barrens Preserve

Identification Comments

Identifying Characteristics

Oligia bridghami is in the family Noctuidae and has a wingspan ranging from 2.8 to 3.1 cm. The forewing is dark, reddish or rusty brown with pale- or violet-gray basal and subterminal areas. Antemedial and postmedial lines and spots are whitish. The hindwing is white or gray with brownish coloration between the median line and the outer margin (Covell, 1984, Beadle and Seabrooke 2012).

Characters Most Useful for Identification

Coloration and patterning on forewings of adults.

Best Life Stage for Proper Identification

Adult.

Diet

The larval foodplants are unknown.

Best Time to See

In northern New York, this species has been observed in late July (New York Natural Heritage Program, 2011). However, it has been noted as being active in July and August in the literature (Covell, 1984).

Bridgham's Brocade Images

Bridgham's Brocade Moth
Janice Stiefel

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Taxonomy

Bridgham's Brocade
Oligia bridghamii (Grote and Robinson, 1866)

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

Additional Resources

References

Beadle, D. and S. Leckie. Peterson field guide to moths of Northeastern North America. Houghton Mifflin Harcourt: New York, NY.

Covell, Charles V. 1984. A field guide to the moths of eastern North America. Houghton Mifflin Company, Boston.

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

McCabe, Timothy L. 2004. Insect biodiversity of a jack pine barrens. A report prepared for the Biodiversity Research Institute, New York State Museum, Albany, NY.

NatureServe. 2012. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer. (Accessed: July 26, 2012 ).

New York Natural Heritage Program. 2011. Biotics database. New York Natural Heritage Program. New York State Department of Environmental Conservation. Albany, NY.

New York Natural Heritage Program. 2023. New York Natural Heritage Program Databases. Albany, NY.

Schweitzer, D.F., M.C. Minno, and D.L. Wagner. 2011. Rare, Declining, and Poorly Known Butterflies and Moths (Lepidoptera) of Forests and Woodlands in the Eastern United States. USFS Technology Transter Bulletin, FHTET-2009-02.

Links

• Butterflies and Moths of North America
• Google Images
• Maritime Grasslands Natural Community Guide
• NatureServer Explorer
• Sandstone Pavement Barrens Natural Community Guide

About This Guide

This guide was authored by: Erin L. White

Information for this guide was last updated on: July 30, 2019

Please cite this page as:
New York Natural Heritage Program. 2023. Online Conservation Guide for Oligia bridghamii. Available from: https://guides.nynhp.org/bridghams-brocade/. Accessed September 23, 2023.