CONCORD, N.H. (AP) – Forest managers in the Northeast and Mid-Atlantic states soon will enlist wasps to help search for a tree-killing insect that has been devastating woodlands.

They plan to use colonies of ground-nesting wasps to search for the emerald ash borer. The larvae in the wasp’s nest feed on wood-boring beetles, including the emerald ash borer, which has killed more than 25 million ash trees in the Midwest and Mid-Atlantic states since 2002 and continues spreading toward the Northeast.

By monitoring which beetles the wasps (Cerceris fumipennis) carry home, foresters hope they will be able to detect emerald ash borer infestations more quickly than by current methods, which could take up to three years.

“The earlier we detect an infestation, the more options we have for management and eradication,” said Mike Bohne, Northeastern Area Forest Health Group Leader in Durham.

He said at least a dozen agencies will participate this summer and fall, in New York, all six New England states, West Virginia, Maryland, Pennsylvania and North Carolina.

Forest experts believe people have helped the spread of the emerald ash borer by carrying firewood long distances. Several states have placed restrictions on the movement of firewood and ash wood products to reduce the spread.

The emerald ash borer is native to Asia. It kills ash trees within a few years after infestation. Infestations continue to spread toward the Northeast through Pennsylvania and Ontario and threaten the entire North American ash family, Forest Service spokesman Glenn Rosenholm said.

The Forest Service considers invasive species one of its top forest threats, costing the United States about $138 billion a year in reduced revenue and forest value, and control and eradication.

Currently, foresters looking for the boring beetle often have to kill trees to try to save a forest. One method involves stripping bark off ash trees, which is costly, time-consuming and kills the tree. A newer method involves deploying purple prism traps high in tree canopies. It is costly and time consuming, but spares the tree.

The wasp method is simpler and cheaper and does not harm trees. And they don’t have to import the wasps. They live in a wide area of the United States, from Canada to Mexico and as far west as the Rockies.

Foresters find a C. fumipennis colony, put a clear plastic cup over the entrance hole, and note what insects the wasp brings back to the colony. If the wasps do not carry an emerald ash borer home within the first 40 returns, it is unlikely there is an infestation, said Canadian Food Inspection Agency Entomologist Philip Careless, in Ontario.

Dr. Stephen Marshall of the University of Guelph in Ontario initiated research into the field after his son noticed about four years ago that a wasp was carrying beetles into a hole in the ground.

“That was the phenomenal leap that he made, using one insect to search for other insects,” said Careless, who studied under Marshall.

He said his own research, based on Marshall’s and other researchers’ earlier works, was to study how practical it would be use the wasps as a way to search for emerald ash borer infestations.

Careless also discovered that the wasp colonies could be moved from spot to spot on trailers to search for infestations.

Maine Forest Service Entomologist Colleen Teerling was one of the many forest health managers who saw a presentation by Careless and realized its potential.

“I think this is the best way we’ve got so far to monitor for emerald ash borer,” she said. “I think it’s one of our best bets.”


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