Forest Preserve District of Cook County (Illinois)
Nature Bulletin No. 31 September 8, 1945 - [edited April,1998]
Forest Preserve District of Cook County
Clayton F. Smith, President
Roberts Mann, Superintendent of Conservation
****:DDT
Large scale experiments are being conducted on selected areas scattered
all over the United States and Canada. The U, S. Fish and Wildlife
Service, the U. S. Forest Service, the Bureau of Entomology and Plant
Quarantine of the Department of Agriculture, and the U. S. Public
Health Service are among the agencies cooperating in these
experiments. DDT is being applied in the form of dust, suspensions,
solutions and emulsions, by means of airplanes, high-powered sprayers,
knapsack sprayers, and hand atomizers.
It is being tested against leaf-eaters, bark beetles, wood borers, termites,
and a number of sucking insects, including mosquitoes and flies. The
experiments indicate that DDT far surpasses any previous used
substance for control of insects harmful to forests, orchards, gardens
and man himself. Its remarkable lasting qualities, even after rains, the
small amount required per acre, and its suitability to application by
plane, would seem to make it the answer to most problems of control of
harmful insects.
BUT, these problems are complex. For instance: what do many birds
feed on? Insects and their larvae. What keeps many harmful insects
under control? Other insects. We now know that certain concentrations
of DDT upon the surface of a pond or lake will kill the mosquito larvae,
but they also kill every fish in that body of water, and the aquatic
insects upon which fish feed. While it may kill the harmful moths in an
orchard, it also kills the bees necessary for the polarizing and fruiting of
that orchard. Its toxic effect in various concentrations, on beneficial
insects, fish and wildlife is a serious problem which requires thorough
investigation. DDT might do more harm than good. Carefully
controlled experiments, watched by scientists specializing in the several
fields involved, must be made.
Certain large areas of the Forest Preserve District are included within
the boundaries of the DesPlaines Valley Mosquito Abatement District
and the North Shore Mosquito Abatement District. We have requested
the officials of these districts not to use DDT in the forest preserves
until more definite knowledge is obtained from the experiments being
carried on by the several government agencies. These agencies have
been requested to supply us with up-to-the-minute bulletins of the
results so obtained.
NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators.
Argonne National Laboratory, Division of Educational Programs, Harold Myron, Ph.D., Division Director.