Moth invasion devastates local forests

The East Oregonian ran a brief on Saturday, Sept. 1, 1973, about a petition drive in northeast Oregon to request the use of DDT in the Wallowa-Whitman and Umatilla national forests to curb an infestation of tussock moths that was devastating hundreds of thousands of acres of Douglas fir. Petitioners claimed that DDT, banned in 1972 for agricultural use, was the only effective insecticide against the moths and that waiting for researchers to find an alternative to the chemical was not a viable option. The Associated Press picked up the story and interviewed La Grande-area residents, who were concerned that the timber industry they relied on for their living would disappear unless the moth infestation could be halted.

EO reporter Marvin Rogers, who was flown over affected regions northeast of Ukiah by the U.S. Forest Service’s Summit Helitack crew, had this reaction: “Brown as far as could be seen, even from the helicopter. The drought had taken care of the undergrowth and the tussock moth had killed every tree in sight. ... It was suddenly plain to see why the Umatilla and Wallow-Whitman national forests and all State Department of Forestry land in northeast Oregon were closed, except to people getting permits.”

The Oregon Board of Forestry, Gov. Tom McCall and U.S. Agriculture Secretary Earl Butz joined the call for the EPA to grant the emergency use of DDT over the affected areas. And senators from Oregon and Idaho brought the issue before the Senate Interior Committee. The EPA had rejected three similar requests earlier in the year because a natural virus normally wipes out the infestation during its three-year cycle; however, virus levels were much lower than normal during the current cycle and the infestation had spread from 172,000 acres in 1972 to more than 600,000 acres by the end of July 1973.

After meeting with state and forestry authorities, the EPA decided it would hold off granting an emergency-use permit until surveys of moth egg masses, a measurement of parasites and growth of moth-killing viruses had been assessed in the spring of 1974. When approval was given Feb. 26, however, it came with a promise by forestry officials that DDT would only be used if absolutely necessary, and only in “high priority target areas” to protect wildlife and sport fisheries.

A group of young entrepreneurs found a way to capitalize on the invasive pests, however. Sixth grade students from West Hills and Hawthorne schools in Pendleton were selling souvenir tussock moth key chains, with actual (dead) moths encased in plastic. By mid-September 1973 they had earned more than $200.