Educator says risk of emerald ash borer invasion this summer is high

bilde-2The likelihood of an emerald ash borer invasion has reached a new high, according to a local expert.

If the emerald ash borer is going to infest the north country, it likely will happen in June as adult insects emerge from trees and take flight, said Susan J. Gwise, horticulture educator at Cornell Cooperative Extension of Jefferson County.

People have good reason to be on guard for the pest this summer, Mrs. Gwise said. The beetle was first detected last summer in Syracuse and Onondaga County, increasing the likelihood of it spreading north. But there is still a greater probability that it will enter the region from the north by arriving from infected regions of Canada, she said. It could easily make the trip across the St. Lawrence River into St. Lawrence County.

“It could be coming at us from both directions, basically,” Mrs. Gwise said. “More than likely it’s going to come from the north, rather than the south, because it could just hop across the river. If it arrives here, it’s likely that we won’t know where it came from.”

The city of Syracuse has addressed the problem by deciding to cut down about 1,000 ash trees — roughly half of the city’s ash population — according to a report this month from

Beetles usually emerge from the bark of ash trees in mid-June, Mrs. Gwise said. They do so when the number of growing degree days climbs to about 450. Growing degree days, which measure heat accumulation, are calculated by taking the average of the daily maximum and minimum temperatures and comparing it to the base temperature on a daily basis over a period of time. As of Thursday, 217 growing degree days had accumulated during the season at Watertown International Airport, according to the Network for Environment and Weather Applications.

Once the insect “starts moving and flying around, it will attach to vehicles,” Mrs. Gwise said. “People have reported them getting on the windshield of cars going 55 miles per hour and staying there.”She said the insects also have been found at railroad yards and environmental officials think trains could be moving them around.

All native ash trees are susceptible to the pest, which leaves a D-shaped exit hole in the outer bark and trunk of trees when it emerges in the summer. Signs of infection include the dying of tree canopies and leaves that are yellowing or browning, according to the state Department of Environmental Conservation. Adult ash borers — at less than an inch long — have metallic green wing covers and a purple or coppery-red abdomen.

Transportation of firewood, which becomes more frequent with summer camping, remains the primary risk of spreading the pest, Mrs. Gwise said. DEC has established a quarantine zone that bans people from transporting firewood into counties across the northern half of the state. In 2008, a state regulation was enacted to restrict the movement of firewood to within 50 miles of its source to prevent the beetles’ spread.

“That’s the whole message to this thing: don’t move firewood around or bring it up here, especially from ash trees,” Mrs. Gwise said, adding that campground operators should be especially careful. “Camps should offer locally sourced woods for campers to buy or have a list of places they can purchase wood within 50 miles. If campers bring wood in, they need to make sure it is all burned on site and not left behind.”

Those who are concerned about potentially infected trees can contact Mrs. Gwise at 788-8450 or

By Ted Booker, Times Staff Writer.