CHAMPAIGN, Ill. - We have much to learn from bad bugs, according to Gilbert Waldbauer, whose book "Insights From Insects: What Bad Bugs Can Teach Us" was published today (Prometheus Books).
"We know a lot about pests, because so much money is spent on their research," said Waldbauer, professor emeritus of entomology at the University of Illinois at Urbana-Champaign. Of the 900,000 known species of insects, a mere 2 percent are considered pests. Just as some plants growing where they are not wanted are considered weeds, insects are considered pests only when they adversely affect people, Waldbauer writes.
For example, homeowners typically think of termites as pests, but in forests termites are important for recycling dead wood.
Waldbauer spent 15 years studying the cecropia moth (Hyalophora cecropia), which he collected by driving along streets in Urbana, Ill., and retrieving cocoons from trees. With its colorful 5- to 6-inch wingspan, the nocturnal cecropia moth is the largest North American moth.
In "Insights From Insects," Waldbauer describes 20 different types of pests. He includes how each pest is destructive to humans, how it sustains itself through feeding, reproduction and avoiding predators, and the various methods that people use to get rid of pests. The book is written for a general audience.
"Many basic biological concepts such as evolution and genetics can be learned through pests," Waldbauer said. For example, he described recent evidence of how a new species of fruit fly is evolving based on how its diet differentiates it from other fruit flies.
Waldbauer uses examples from history, his career and conversations with his entomologist colleagues to illustrate what we can learn from bad bugs.
Many of the pests he describes are found in Illinois, including the corn rootworm. Other regional insects also are mentioned, such as the evergreen bagworm that spans the east coast of the United States and stretches westward to Nebraska and Louisiana. Other pests with wider ranges, such as disease-toting mosquitoes, produce-feasting fruit flies and sap-sucking aphids, also are featured.
The history of how many insects were spread to the United States also is discussed. For example, in 1869, the gypsy moth (Lymantria dispar) arrived in Medford, Mass., from Europe when the French naturalist Leopold Trouvelot brought them to use in silk culture experiments. A few escaped as caterpillars and their descendants thrived, leading to rampant defoliation 20 years later.
Such destruction has led people to devise various methods to exterminate bad bugs.
"The least creative way to get rid of bad bugs is by using insecticides," Waldbauer said. Biological control, a practice in which natural predators are introduced, is a more creative and effective way to control pests, he said. In the book, Waldbauer explains many historic and recent examples of how people control pests without insecticides.
For example, in 1886, the cottony cushion scale (Icerya purchasi), accidentally imported from Australia, threatened California's early citrus industry. At times these pests, whose sucking beaks are permanently attached to and suck juice out of leaves, infested trees so densely that the trees appeared to be covered with snow.
Introduction of 129 Australian ladybird beetles (Rodolia cardinalis), a natural predator of the scale, to a Los Angeles orange grove destroyed almost all of the pests within six months. "By the end of 1889, the scale was no longer a threat anywhere in California," Waldbauer wrote.
Waldbauer also recounted a more recent study in which tsetse flies were feasting on and causing infections in cows in Zimbabwe. Entomologists led by Steve Torr of the University of Greenwich in the United Kingdom placed 60,000 fake cows made of cloth and steeped in insecticide on cattle ranches. Instances of infections dropped from 10,000 to 50 per year. These findings were reported in the journal Science in 2001.
Not only do insects interact with people, some insect species share characteristics with humans, Waldbauer said. For example, the tsetse fly has an analogue of a mammalian uterus. "Milk-secreting glands that empty into the 'uterus' feed the developing larva. Tsetse milk is white and chemically similar to human or cow's milk," Waldbauer wrote in a chapter titled "Guaranteeing descendants: The role of parental care."
Waldbauer emphasizes that insects can be useful to humans. For example, he said, maggot therapy has been used to remove gangrenous tissue while leaving healthy tissue intact. Because of the increasing prevalence of bacterial resistance, the therapy has been used recently to replace antibiotics.
Since retiring in 1995, Waldbauer has written several books, including "The Handy Bug Answer Book," "What Good are Bugs" and "Insects Through the Seasons." He is now completing work on his next book, "Aquatic Insects: Bugs In and Over the Water."
Meredith Waterstraat illustrated "Insights From Insects." Waterstraat, a former Illinois graduate student in mathematics education, also illustrated "What Good are Bugs." Waldbauer and Waterstraat began working together after he saw and was intrigued by her paintings of beetles at the Anita Purves Nature Center in Busey Woods in Urbana.