FIFRA Definition of “Pest” (1) any organism that interferes with the activities and desires of humans or (2) any other form of terrestrial or aquatic plant or animal life or virus, bacteria, or other micro-organism (except viruses, bacteria, or other micro- organism on or in living man or other living animals) which the Administrator declares to be a pest under section 25(c)(1).
Each pest species has a given status within a complex • Key pests • Minor pests • Secondary pests • Occasional pests • Potential pests • Chronic pests • Migrants • Accessory Species • Vectors (Pest status often linked with pathogen) • Alternate Hosts
IPM Defined IPM – A system that maintains the population of any pest, or pests, at or below the level that causes damage or loss, and which minimizes adverse impacts on society and environment. Attempts to balance the benefits of pest control actions with the costs when each is considered in the broadest possible terms.
During the 1940’s • 1940 – DDT patented as an insecticide • 1942 – BHC found insecticidal • 1943 – 2,4-D found effective as a herbicide • 1946 – Gerhard Schrader hired by Bayer • 1946 – Houseflies found resistant to DDT
“The most discussed of the new insecticides is dichloro-diphenyl-trichloroethane, shortened to DDT but also called Guesarol. This compound has remarkable power to kill insects, particularly body lice-the ‘cooties’ of World War I. The prevalence of typhus, carried by body lice, in the Mediterranean theater of this war has emphasized its value. DDT’s effectiveness in war may well be overshadowed by its value in peace. Painstaking investigations have shown it to be signally effective against many of the most destructive insects that feed upon crops.”Scientific American, July 1944.
BiomagnificationThe concentration of pesticides in higher levels of food chains
Trophic Levels Based on: Mader, S., Inquiry Into Life, McGraw-Hill Most food chains consist of four trophic levels
DDT in Food Chain DDT is concentrated as it moved up food chain This is because energy is lost (from respiration) as go up food chain but DDT is not Based on: Campbell et al, Biology: Concepts and Connections, Benjamin Cummings
Overview of Lesson • Pests, DDT and biomagnification • DDT, eagles and falcons • Endangered Species Act • Organic foods
Bald Eagle • Once was widely • distributed over U.S. • As a top carnivore it feeds on fish • Swoops down and captures fish off the surface of the water Photo courtesy of Texas Parks and Wildlife Department
Scientists discovered that DDT was • concentrated in the bald eagle • DDT affected the eagle’s ability to reproduce Photos courtesy of Texas Parks and Wildlife Department
Scientists found that the eagle eggs had thin egg shells and broke easily Nests contained broken, rotten eggs The number of young produced per breeding pair was reduced
Population of adult eagles declined to 4,000 and the eagle was listed as “Endangered” Photo courtesy of Texas Parks and Wildlife Department
During 1950’s Organic chemical pesticides become routine on all crops • Viewed as “modern” farming • Low risk, “cost of business” • Few/no regulations • High prices/demand for US exports • Problems would not be addressed until 1962
Problems Arising During the 1950’s • Pest Resistance • Bird/Fish Kills • Human Poisonings • Secondary Pests • Biomagnification
As the Effects Spread … • Public became increasingly negative toward chemical companies. • 1970 – EPA established. • 1972 – DDT banned (biomagnification) • 1973 – IBP project started • Emphasized pest control as a system • Introduced pest modeling/decision tools • Only for insects
IPM Concept Solidifies in the 1970’s • 1975 – First textbook, Metcalf & Luckman (former had been criticized in SS) • 1978 – CIPM project replaces IBP • Included weeds & plant pathogens • Included economic analyses • 1978 – KY statewide IPM program began