New York Natural Heritage Program
Bridgham's Brocade
Oligia bridghamii (Grote and Robinson, 1866)
Insects

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 gypsy moths. 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.