categories of insecticide. In 1983, the Food and
Drug Administration (FDA) found DDT in 334
out of 386 domestic fish tested, even though DDT
had been banned since 1972. In 1984, the cancer-
causing fungicide ethylene dibromide (EDB) was
banned, after it was found in prepared cake mixes
and on citrus fruit.
Birth of Biopest Control in the 1980’s Biological
methods of pest control had been used in the United
States since the nineteenth century, when California
imported Australian ladybugs to eat pests killing eu-
calyptus trees. From 1959 to 1980, stingless wasps
from Europe and Asia were used very successfully
against alfalfa weevils in eleven states. By the first half
of the 1980’s, biopesticides had become a viable al-
ternative to chemicals, spurring a national trend.
Start-up companies produced successful products in
California and on the East Coast. The public, fright-
ened by media warnings and distrustful of govern-
ment safety standards, was eager to find such alter-
natives to potentially toxic chemicals.
Biopesticides use four approaches: The most
common is flooding infestations with laboratory-
grown natural predators that specialize in eating tar-
get insects, mites, or weeds. A second is spraying
harmless substances that are nevertheless deadly
to pests—insecticidal soap orBacillus thuringiensis
(BT), for example. A third approach is using passive
traps that pests cannot escape from, usually incorpo-
rating pheromones to coax them inside. The most
complex approach is genetically engineering plants
to resist or kill pests, such as implanting a gene in
corn that causes it to kill corn borers.
Purists advocated using nothing but natural con-
trols. Organic farms appeared, their operators weed-
ing by hand, using bio-controls to combat pests, and
working mounds of compost into their soil instead
of chemical fertilizers. These farms stayed small be-
cause of the labor required to maintain them. “Or-
ganic” fruit and vegetables appeared in supermar-
kets, for prices much higher than were charged for
“conventional” produce. Major food marketers, ea-
ger to capitalize on the trend toward spending more
for more “natural” foods, began boxing “natural”
food products, particularly breakfast cereals. Even-
tually, the government would regulate the use of la-
bels such as “natural” and “organic.”
Impact By the early 1980’s, biopesticides were the
control method of choice countrywide. BT, a natu-
rally occurring bacteria lethal to caterpillars, was used
to control gypsy moths and spruce budworms. The
U.S. Forestry Service switched to BT under public
pressure after one of its trucks accidentally dumped
insecticide into the Columbia River, killing seventy
thousand trout. A variant, BTI, was used to kill mos-
quitoes and blackfly larvae. Predatory nematodes
(microscopic soil worms) were used to control Colo-
rado potato beetles. Ladybugs were sold by the mil-
lions to eat aphids. Predatory wasps were imported to
kill mole crickets and mealy bugs. Florida imported
weevils to eat water hyacinths. In 1987, the govern-
ment spent more than $800 million on biological
pest-control research projects. Use of farm chemicals
was gradually reduced, and large companies entered
the biotech field. Biopesticides became widely avail-
able not only for farmers but also for home garden-
ers, who could purchase them at nurseries and in
popular gardening and lawn-care catalogs.
Large-scale farming cannot profitably sustain
complete biological controls. However, the rising
cost of chemicals and the laws limiting their use
drove farmers in the 1980’s to adopt integrated pest
management (IPM) strategies. IPM requires crop
rotation, surface tillage that does not disturb deep-
lying weed seeds, cleaning debris housing over-
wintering pests, exploiting natural predators and
nontoxic substances to kill weeds and insects, crop
rotation, and crop varieties resistant or repellant to
pests. Chemicals are used only if infestations get out
of hand. The natural predator portion of IPM is ini-
tially more expensive than chemicals, but it proves
less expensive over time, as introduced predators
stay in farmers’ fields and need not be reintroduced
every year.Further Reading
Altieri, Miquel Angel, and Clara Ines Nicholls.Bio-
diversity and Pest Management in Agroecosystems.2d
ed. New York: Food Products Press, 2004. A hand-
book about large-scale farming using biopesti-
cidal techniques.
Brown, Michael H.A Toxic Cloud. New York: Harper-
Collins, 1987. Journalistic account of cases of poi-
soning by dioxin and other chemicals.
Carson, Rachel.Silent Spring. 40th anniversary ed.
Boston: Houghton Mifflin, 2002. The 1962 book
that ignited the antipesticide movement, written
by a woman who has become the icon of the anti-
chemical movement.The Eighties in America Biopesticides 113