Battling the Budworm

There is a biological time bomb in Maine's north woods armed with a fuse set to explode it in a month. Awakened by the warming sun, billions of tiny spruce-budworm larvae will hatch and turn into ravenous caterpillars, ready to eat all the needles and buds on spruce and balsam fir, hemlock and tamarack. Before their appetite is sated, the budworms are expected to chew their way through some 6 million acres of conifers. For 3.5 million of those acres--an area larger than Connecticut--this will be the third straight year of defoliation, and even healthy trees cannot survive such continuous attack.

Descending Clouds. Though the budworm infestation has been a fact of Maine's forest life for years, it grew to epidemic proportions last July after the caterpillars became moths. In addition to Maine's native budworms, hordes more were swept southeast on prevailing winds from Canada, where 75 million acres are also infested. "Clouds" of the insects--one measured 64 miles long by 16 miles wide--were tracked by the U.S. Weather Service's radar operators. When the moths landed, they clogged factory ventilators and auto radiators; their crushed bodies coated highways with a slippery, accident-causing goo; in some places, people shoveled the bugs off their porches like snow. But most of the moths ended up in the vast forests, where they quietly laid billions and billions of eggs in preparation for this spring's attack, which promises to be the worst in 56 years.

If the trees on the 3.5 million acres are killed, the U.S. will lose enough wood to have built 1.3 million houses or enough paper to have kept 92 million Americans in newspapers, tissues and wrapping for a year. That is not the only potential loss. Maine would be deprived for the 40 years needed for forest regeneration of at least $13.6 million a year in taxes from the forest-products industry. Workers and businesses serving the timber industry could lose another $106 million per year. Beyond that, Maine's $450 million-a-year tourist industry will suffer; no campers or hunters will want to go into a gloomy wasteland of dead trees. In the competition with the budworm, concludes Lester De-Coster, New England regional manager of the American Forest Institute, "man cannot afford to lose."

Trouble is, man's prospects for winning are not very bright. Ever since the use of DDT was banned in 1967, Maine has had few weapons in its battle against the budworm. Environmentalists have suggested gradually cutting down the spruce and balsam trees to deny the caterpillar its food and replacing them with hardwood varieties immune to attack. But that plan is not practical; spruce and balsam are best adapted to the north woods and, says Fred Holt, director of Maine's bureau of forestry, "they always come back when you plant something else." Biological controls--most notably one that involves spraying the foliage with a solution containing Bacillus thuringiensus, a bacterium that kills only caterpillars--are still too expensive and difficult to apply over a wide area.

That leaves only one immediate alternative: spraying with short-lived pesticides that do not harm other forms of wildlife. Assuming that Maine officials can find enough such chemicals to douse 3.5 million acres this spring, they still must face the fact that the insecticides will kill only a fraction of the moths and that others will take their place next year, attracted by the trees that survive this spring's onslaught. Thus Maine can only wage a holding action against the budworm and hope that nature will lend a hand with a caterpillar-killing cold snap next month.

This file is automatically generated by a robot program, so viewer discretion is required.