PITTSBURGH (AP) — With insect pests are causing more damage than expected to valuable black cherry trees and other species in the Allegheny National Forest in Pennsylvania, more tree planting and other measures in several areas are being proposed.

The cherry scallop shell moth, fall webworm and other pests are causing greater-than-expected tree defoliation, mortality and regeneration problems, The Pittsburgh Post-Gazette reported.

The U.S. Forest Service is therefore proposing more aggressive timbering and tree planting in three existing project areas in the Marienville District of the 517,000-acre forest in Elk, Forest, McKean and Warren counties in northwestern Pennsylvania.

Those proposals would change tree thinning treatments to “remove, in stages, nearly all of the trees in 94 forest stands covering 2,149 acres.

Marienville planning team leader Kevin Treese said black cherry, white ash, oak and beech trees in the state’s only national forest are experiencing defoliation, crown dieback and tree mortality due to multiple pests, some invasive species like the emerald ash borer and others native species like the cherry scallop shell moth.

“We’ve got a whole host of pest problems but the cherry scallop shell (moth) is the new one, the big one,” Treese said. “We need to take a more active role in regulation of the forest. And we need to do it before we lose the seed sources.”

A state Bureau of Forestry flyover survey last summer found 48,660 acres of black cherry in the national forest defoliated by the sherry scallop shell moth, almost three times the 17,000 acres eaten by the moth the year before, as well as 56,230 acres of privately owned and state forest land defoliated by the moth.

The national forest has historically relied on natural regeneration, but Treese said reforestation of the three project areas will necessitate supplemental plantings of black cherry, a variety of conifers, red maple, sugar maple, yellow poplar and oak.