Biodegradable Insecticides in Forestry
181
7.9. CONCLUSIONS
The R&D process for selecting, evaluating, and applying insecticides in
forestry is a massive web of legislation, regulation, chemistry, biological phenomena, and environmental awareness. The pathway used in the R&D process
employs several critical steps and attention to appropriate staging. Some of the
critical steps are determination of the relative toxicity of the insecticide to the
target insect, prior registration for agriCUltural use, small-scale field testing to
determine efficacy under field conditions, large-scale field tests to more accurately define dosage and efficacy, safety tests under field conditions to evaluate
the impact of the candidate insecticide on a limited number of nontarget species,
and finally, an operational test to evaluate the effectiveness of an efficacious
insecticide for suppression of an outbreak:. The cost of each step in the pathway
increases in the selection of a new insecticide. As a result, staging the tests in
the order described assists in the avoidance of unsuccessful costly tests.
The state of the art is the most advanced for suppression of defoliating
insect pests. Several insecticides are now registered for use against these pests:
carbaryl, acephate, and trichlorfon. Diflubenzuron is emerging as a new noncholinergic-type insecticide for forestry use.
Large-scale suppression of bark beetles with insecticides does not seem
feasible with today's insecticides, and suppression programs are more effective
that employ an integrated pest management approach, an approach that places
a major emphasis on silvicultural practices.
New pyrethroid insecticides are frequently the most toxic compounds tested
at the laboratory level on most forest insect pests. Only a limited number of
small-scale field tests have been conducted with the pyrethroids, and further
testing needs to be done at this level.
REFERENCES
Akesson, N. B., and Yates, W. F., 1976, Physical parameters relating to pesticide application, in:
Pesticide Spray Application, Behavior, and Assessment: Workshop Proceedings (R. B. Roberts,
ed.), pp. 4-26, U.S. Department of Agriculture Forest Service General Technical Report PSWIS, Pacific Southwest Forest and Range Experiment Station, Berkeley, California.
Barger, J. H., 1978, Smaller European elm bark beetle elm bole bioassay tests, Insecticide and
Acaricide Tests 3:142.
Barry, I. W., Tysowsky, M., Jr., Orr, O. F., Ekblad, R. B., Marsalis, R. B., and Ciesla, W. M.,
1976, Impaction of Zectran particles on spruce budworm larvae a field experiment, in: Pesticide
Spray Application, Behaviour, and Assessment: Workshop Proceedings (R. B. Roberts, ed.),
pp. 40-47, U.S. Department of Agriculture Forest Service General Technical Report PSW-1S,
Pacific Southwest Forest and Range Experiment Station, Berkeley, California.
181
7.9. CONCLUSIONS
The R&D process for selecting, evaluating, and applying insecticides in
forestry is a massive web of legislation, regulation, chemistry, biological phenomena, and environmental awareness. The pathway used in the R&D process
employs several critical steps and attention to appropriate staging. Some of the
critical steps are determination of the relative toxicity of the insecticide to the
target insect, prior registration for agriCUltural use, small-scale field testing to
determine efficacy under field conditions, large-scale field tests to more accurately define dosage and efficacy, safety tests under field conditions to evaluate
the impact of the candidate insecticide on a limited number of nontarget species,
and finally, an operational test to evaluate the effectiveness of an efficacious
insecticide for suppression of an outbreak:. The cost of each step in the pathway
increases in the selection of a new insecticide. As a result, staging the tests in
the order described assists in the avoidance of unsuccessful costly tests.
The state of the art is the most advanced for suppression of defoliating
insect pests. Several insecticides are now registered for use against these pests:
carbaryl, acephate, and trichlorfon. Diflubenzuron is emerging as a new noncholinergic-type insecticide for forestry use.
Large-scale suppression of bark beetles with insecticides does not seem
feasible with today's insecticides, and suppression programs are more effective
that employ an integrated pest management approach, an approach that places
a major emphasis on silvicultural practices.
New pyrethroid insecticides are frequently the most toxic compounds tested
at the laboratory level on most forest insect pests. Only a limited number of
small-scale field tests have been conducted with the pyrethroids, and further
testing needs to be done at this level.
REFERENCES
Akesson, N. B., and Yates, W. F., 1976, Physical parameters relating to pesticide application, in:
Pesticide Spray Application, Behavior, and Assessment: Workshop Proceedings (R. B. Roberts,
ed.), pp. 4-26, U.S. Department of Agriculture Forest Service General Technical Report PSWIS, Pacific Southwest Forest and Range Experiment Station, Berkeley, California.
Barger, J. H., 1978, Smaller European elm bark beetle elm bole bioassay tests, Insecticide and
Acaricide Tests 3:142.
Barry, I. W., Tysowsky, M., Jr., Orr, O. F., Ekblad, R. B., Marsalis, R. B., and Ciesla, W. M.,
1976, Impaction of Zectran particles on spruce budworm larvae a field experiment, in: Pesticide
Spray Application, Behaviour, and Assessment: Workshop Proceedings (R. B. Roberts, ed.),
pp. 40-47, U.S. Department of Agriculture Forest Service General Technical Report PSW-1S,
Pacific Southwest Forest and Range Experiment Station, Berkeley, California.