. Eastern forest insects . Figure 4. F-517833 -Mist blower applying insecticide to pine trees in a seed orchard. —a period during which a large number of new insecticides and methods of application have come into extensive use, and during which outbreaks covering hundreds of thousands of acres of forest have been suppressed. As effective as insecticidal control has been, however, it has not proved to be an unmixed blessing. It has given rise to many complex problems associated with known or suspected adverse side effects caused by some of the more com- monly used chemicals. This stems from the
. Eastern forest insects . Figure 4. F-517833 -Mist blower applying insecticide to pine trees in a seed orchard. —a period during which a large number of new insecticides and methods of application have come into extensive use, and during which outbreaks covering hundreds of thousands of acres of forest have been suppressed. As effective as insecticidal control has been, however, it has not proved to be an unmixed blessing. It has given rise to many complex problems associated with known or suspected adverse side effects caused by some of the more com- monly used chemicals. This stems from the fact that these chemi- cals, like most other chemicals used as insecticides, are non-specific and can be expected to be harmful to at least some other exposed animal species. The problem is compounded in that some chemical insecticides are very persistent, that all of the material applied in a given environment may not remain in that environment and that free-ranging animals cannot be excluded from sprayed areas. Public awareness of known and possible hazards associated with the use of these chemicals in insect control projects, therefore, has given rise to a considerable degree of concern over their con- tinued widespread use. Efforts are unceasing to discover and develop new and safer insecticides and to determine the danger points of insecticidal accumulations in the tissues of various forms of wildlife, as a basis for preventing undesirable damage to the biota. Application techniques and equipment are being refined in order to provide better control of the placement of insecticides in the environment and to further lessen the dangers of undesirable side effects. Studies are being made to improve sampling and biological evalu- ation techniques as a basis for improving the timing of application and to insure that insecticides are applied only when and where they are needed. The rapid changes occurring in the development and use of insecticides in forest insect control make
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Keywords: ., bookcentury1900, bookcollectionbiodive, booksubjectforestinsects
