Tracing the Roots of a Gypsy

Abstract

Early this summer, a team of U.S. scientists set out from Beijing, the capital of the People's Republic of China, and traveled for two months across 9,000 miles of the remote northeastern provinces of Jilin and Heilonjiang. Their schedule was a rigorous one -breakfast at 6:15 each morning, followed by several hours bumping over dusty dirt roads in a small jeep. researchers, accompanied by their Chinese hosts, stopped for hours at a time to scour surrounding woodlands with their collecting nets and boxes. At nightfall, they stopped in tiny rural villages for supper. Then the researchers went back to work for another two or three hours before finally falling asleep. Targets of this group's unusual search were the hundreds of large, hairy caterpillars they collected every day -larvae of the well-known ubiquitous forest pest, the gypsy moth (Lymantria dispar). Caterpillars were collected from China to be scrutinized for natural enemies in that country parasites, predators and diseases. The gypsy moth is the major problem we have in northeastern hardwood forests today, says William E. Wallner, a U.S. Department of Agriculture entomologist and member of the scientific team that traveled to China. Last year the gypsy moth defoliated nearly 13 million acres in New England, according to the USDA. While the 1982 figures have not yet been fully compiled, a USDA Animal and Plant Health Inspection Service spokesman said that at least 7 million acres were defoliated, not counting New Hampshire or Vermont. While interest has peaked in the past two years the greatest defoliation ever occurred in 1981 the gypsy moth remains a chronic problem, says Ralph E. Webb, a research entomologist with the USDA's Agricultural Research Service. Lymantria dispar populations run in cycles, he says, and even if defoliation turns out to be half of what it was last year, 1982 will probably be the second worst year in history. In addition to the threat they pose to forest and ornamental trees, gypsy moth larvae are a human nuisance, covering roads, lawns, swimming pools and houses during heavy population outbreaks. Their Young gypsy moth larvae feeding on a red oak leaf.