Methods for Assessing the Impact of Fog Oil Smoke on Availability, Palatability, and Food Quality of Relevant Life Stages of Insects for Threatened and Endangered Species

摘要

Protection of threatened and endangered species (TES) and their habitat on U.S. Department of Defense (DoD) lands while sustaining the use of those lands for military training is a major goal of the Strategic Environmental Research and Development Program s (SERDP) conservation mission. Important components of troop training exercises at military training installations are generation of fog oil (FO) smoke and maneuvers under obscurant cover. To comply with the Endangered Species Act, the impact of fog oil releases on avian TES (or surrogates) have been evaluated in both field and laboratory studies. Although no direct acute effects on avian species have been observed, concern has been raised regarding a possible indirect impact via reduction in insect populations used as a food source for these species. This concern arises from the fact that petroleum oils of similar composition to that of fog oil have long been used to kill insect pests. These oils particularly target soft-bodied insects, eggs, and larvae that are important dietary components of several avian and bat TES inhabiting military lands. To determine if training exercises with FO smoke causes depletion of TES food resources, a method was developed to evaluate the impact of FO aerosols on the survival and palatability/activity of the consumed life stage of representative insect prey species. The method was also applied to antecedent life stages to evaluate deficits in the production of the consumed life stage. Because FO deposition in the foraging habitat of the TES of concern can be affected by wind speed and canopy structure, the influence of these key environmental factors on the population responses was also characterized.