Chapter 7 Summary

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Last Updated on May 5, 2015, by eNotes Editorial. Word Count: 652

This chapter examines the collateral damage that ensues when communities and municipalities short-sightedly use chemicals to target unwanted pests. In an effort to rid the area of Japanese beetles, the state of Michigan enacted a spraying program that devastated some bird populations. Although the beetle population evidenced “no appreciable” increase during a thirty year period, an organized spraying program began to drizzle aldrin pellets from the air. The state of Michigan provided funding for “the manpower and supervising the operation,” while the federal government supplied the insecticide.  

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A documented record of natural controls had been proven effective. Still, a large-scale spraying campaign was begun in the state of Michigan in the 1950s. Public concerns mounted as the state prepared to enact the spraying campaign. To quell the fears regarding the use of the lethal chemical, aldrin, one official was recalled to have stated that the use of aldrin was “a safe operation.” Thus, the state initiated the campaign, relying on state pest control laws, which did not require permission from landowners prior to commencing the spraying program.

The spraying began and citizens began protesting immediately. They complained that granules of insecticide beat down upon pedestrians as they walked along the street, covered the sidewalk and grasses, and pounded the rooftops of homes. These initial calls caused a minor stir and efforts were made to reassure an unsettled public. However, more troubling calls reported “an alarming number of dead and dying birds.” In addition, following the spraying, dogs, cats, and other domesticated animals were treated for a myriad of ailments. Worse than the ailing animals, however, were human patients who suffered from symptoms including “nausea, vomiting, chills, fever, extreme fatigue and coughing.” These people reported to their physicians that they became ill only after watching the planes spray the area.

The destruction in Michigan paled in comparison to the devastation caused by the use of dieldrin in Illinois. Dieldrin was also used to rid the area of Japanese beetle infestations. Following a 14,000-acre initial application, the Sheldon area of Illinois saw a roughly 131,000-acre treatment area within a six-year period. The havoc began with earthworms and beetle grubs, who digested the chemicals from the soil and lay dead on the surface of the ground. Birds that bathed in puddles or drank rainwater began to fall dead. Surviving birds were sterilized and small ground mammals, such as squirrels, muskrats and rabbits died violently. Most surprisingly, however, “ninety percent of all farm cats” died during the first season of spraying. Reports indicated that these animals, along with herds of sheep and beef cattle, were ravaged by the dieldrin spraying campaign.

In contrast to the use of chemicals, from 1920 until 1933, “some 34 species of predatory or parasitic insects” were imported into the country in order to impose natural control on the Japanese beetle population. Among the imported insects, one species of wasp, the Tiphia vernalis, was particularly effective. The wasp disables the beetle grub through the use of a paralyzing fluid that contains an egg. The developing larva is then nourished on the paralyzed grub. In the areas where the wasp was transplanted, the beetle population remained under control.

A similar outcome was found in areas where a bacterial disease that affects the beetles was introduced into the environment. The disease, known as “milky disease,” was spread throughout the Japanese beetle population through artificial means. Grubs infected with the disease were ground up and mixed into a chalky mixture that was spread over the habitats of the Japanese beetle. This method was proven effective in controlling the beetle. It was an especially appealing option because “milky disease” is cause by a “highly specific organism” and is harmless to other insects. Moreover, the bacterial spores are viable long after they have been introduced in the environment. Despite the success of these forms of effective natural control, however, deadly chemicals have been preferred because they provide more immediate results. 

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