Chemical Control Agents Used Against the Gypsy Moth Essay -- Gypsy Mot

Chemical Control Agents Used Against the Gypsy Moth The gypsy moth (Lymantria dispar) is a highly disruptive species that can, and has played a distinctive role in the lives of many organisms. Included in these organisms are various deciduous trees and shrubs, wildlife species that share the same environment, and even humans. The gypsy moth destroys the beauty of woodlands via defoliation, alters ecosystems and wildlife habitats, and disrupts our own lives. It should therefore come as no surprise that the U.S. Department of Agriculture and many other agencies have taken huge steps to help diminish populations of this small, yet persistent species. In an effort to control these overwhelming populations, five chemical control agents have been used to suppress and/or eradicate the gypsy moth. Following, is a discussion of each chemical and their potentially hazardous effects on humans. The first chemical control agent is Bacillus thuringiensis var. kurstaki (B.t.k.); a bacteria isolated from diseased silk worms and flour moths. The potency of B.t.k. varies among insects and readily destroys lepidopteran larvae within approximately one hour of ingestion. More than 1 million pounds of B.t.k. is applied annually in the U.S., primarily via aerial spraying, but also by ground spraying. It does not persist long in the environment (losing its activity by 50% within 1-3 days), has not been seen to replicate in gypsy moth predators, and does not accumulate in the soil. There seems to be a low level of concern regarding human B.t.k. exposure, although B.t.k. formulations have caused eye, skin, and respiratory tract irritations, especially in ground workers. Some claims reveal that a majority of these workers were not equipped with ... ... 8) U.S. Department of Agriculture, Forest Service, Northeastern Area State and Private Forestry, Summary: Final Environmental Impact Statement, Radnor, PA, 1995. 9) U.S. Department of Agriculture, Forest Service and Animal and Plant Health Inspection Service, Gypsy Moth Suppression and Eradication Projects, 1985. 10) U.S. Department of Agriculture, Forest Service and Animal and Plant Health Inspection Service, Gypsy Moth Managment in the U.S.: a cooperative approach. Environmental Impact Statement; Appendix F Human Health Risk Assessment, 1995. 11) Wargo, Phillip M., Defoliation by the Gypsy Moth: How it Hurts Your Tree, U.S. Department of Agriculture, No. 223, 1974. 12) White, William B., Hubbard, Schneeberger, and Raimo, Technological Developments in Aerial Spraying, U.S. Department of Agriculture, No. 535, 1974.