Bats, Beetles, and Bugs . There are many good reasons for farmers, and indeed all of us, to welcome and encourage these bats in our fields and yards, but the best reason is because of what big brown bats eat. Some of their major foods are beetles and true bugs, most of which are significant agricultural pests. These estimates are very conservative and do not include the many other insects eaten.
Cucumber beetles are one of the most significant agricultural insect pests in the United States.
Their appetite costs farmers in the United States about one billion dollars annually. These pests are a particularly favored prey of the big brown bat and often total up to one third of the food eaten by a typical midwestern big brown bat colony. If such a colony ate the previously mentioned 38,000 adult cucumber beetles in a season, it would also mean that about 18 million rootworms were not produced. Both stages of June bugs are also highly injurious to plants. Stinkbugs are often pests in orchards and on soybeans.