Silent Spring: Chapter 10 Summary & Analysis

Aerial spraying of pesticides has very rapidly become common practice, and is largely unquestioned and indiscriminate. However, recent, disastrous campaigns - against the gypsy moth in the Northeast and the fire ant in the South – have caused some understandable public misgivings about such programs.

Released accidentally in 1869, the gypsy moth spread throughout New England via wind and shipping. The Adirondacks and thirteen imported parasites and predators had successfully halted its spread further, but the Agriculture Department still called for widespread spraying with the goal of ‘eradication.’ By 1957, 3 million acres of forests, farmland, and suburban lawns were being sprayed despite an abundance of public complaints.

Robert Cushman Murphy, a notable ornithologist, led a campaign against the spraying, seeking a court injunction. The movement was unsuccessful, but Justice Douglas wrote a dissenting opinion in support of their claims. After the spraying, on the Waller farm in Westchester, New York, although officials had assured the property owner that her holdings would not be sprayed, milk samples taken from cows on her farm showed DDT contamination. There is a lack of consumer protection from such polluted milk.

Paid by the gallon sprayed rather than by the acre covered, pilots hired to perform the spraying did so indiscriminately, with no regard for what was beneath them. As a result, unintended casualties on the ground were hard to avoid. Hundreds of bee colonies died and crops suffered without these vital pollinators. Overall, the program was disastrous, and was curtailed in following years. In a pattern that mirrors what we have seen before, the targeted gypsy moth reappeared in the area despite renewed spraying.

In the South, the fire ant, which Carson argues was not in reality a very important pest, and may actually have helped in controlling other pests more harmful to agricultural interests, became the focus of attention after an intensive propaganda campaign that resulted in a “sales bonanza” in pesticides. This included the production of a horror film depicting the terrible, and potentially deadly effects of a fire ant bite – even though the record of bites in the area was nearly non-existent. Despite widespread protests, no research was done before the launch of the million acre aerial campaign in 1958.

As we have seen in other cases, aerial spraying resulted in massive mortality in birds and ground animals, as well as livestock, throughout the Southern United States. Despite denials from the Department of Agriculture, ninety percent of dead bird specimens studied by the Fish and Wildlife Service contained residue of the sprayed pesticides dieldrin or heptachlor. Dr. Otis Poitevint, a veterinarian, saw many sick farm animals, including a calf that was exposed via his mother’s milk – and this raises new concerns about transmission to human children.

In 1959, the FDA banned any residues of epoxide on food—this new regulation prompted the ‘discovery’ at the Department of Agriculture that, in 1952, biologists had found that heptachlor, the chemical most widely used against the fire ants, transforms into the more toxic epoxide after a short period in animal or plant tissue. Even though this data had existed for seven years, no one involved in the fire ant campaign seems to have done enough research before spraying began to notice it in the academic literature. Public officials subsequently pushed back against the spraying program, and it tapered off amid general outcry.

In the wake of the program, fire ants were by no means ‘eradicated,’ and in fact their numbers seem to have increased in some states. A return to more “sane” methods has occurred since the end of the aerial campaign, with selective, targeted chemical treatment of individual mounds, which generates only one quarter the cost of aerial spraying and is much less destructive to the surrounding ecosystem.