Leaf-eating gypsy moths captured in Grants Pass
GRANTS PASS, Ore. (AP) — For the third consecutive year, gypsy moths have turned up near Grants Pass. In fact, half of the state total of 14 detections this year came from one single trap in the Azalea Drive area a few miles west of town.
The leaf-eating moths don’t pose an immediate threat at this level, but their presence makes foresters nervous.
“We’re catching these before they have populations high enough to damage trees,” said Clint Burfitt, manager of Oregon Department of Agriculture’s Insect Pest Prevention and Management Program.
In large numbers the moths, which were imported to Massachusetts from Europe in 1869, are among the worst tree defoliators around. In their caterpillar stage, they can eat as much as a square foot of leaves per day.
Of the 14 caught in Oregon this year, 12 are the European variety, while two of the more destructive Asian gypsy moths were caught in the Portland area.
That’s not exactly an infestation — more than 19,000 were trapped in Lane County alone in the mid-1980s — but it is cause for concern.
“This is an exceptionally destructive insect that would change the health of our forests, making them far more vulnerable to other invasive plant issues, causing a loss of foliage on trees as well as damaging agricultural-related industries that would face quarantines should the gypsy moth get established,” Burfitt said in a news release from the Department of Agriculture.
The Department of Agriculture put out 15,000 traps statewide in the spring. In addition to the moths found in Portland and Grants Pass, there were three others in the Portland area, one in Forest Grove and one in West Linn.
According to the agency, Asian gypsy moth females can fly, unlike the European strain, which could lead to more rapid infestation and spread. The Asian strain also has a larger appetite for what grows in Oregon, including conifers.
Only three Asian gypsy moths had been detected in Oregon before this year — a single catch in Portland in 1991, one in Portland’s Forest Park in 2000, and one in St. Helens in 2006.
The European strain most often arrives when people move from the Midwest and East where the moth populations are far higher.
The seven moths caught here indicate a breeding population exists, Burfitt said.
In 2013 only two moths were caught, and last year it was three, in the same area. Burfitt said it’s possible to find the “epicenter” where females are laying eggs.
As of now, there are no plans to spray, but there is the possibility of moth eradication projects next year in Josephine County and Portland, the ODA said.
For many years spraying for the gypsy moth was done annually in Oregon, but the most recent eradication occurred in 2009. Prior to this year’s 14 detections, there were only seven detected in the state from 2012 through 2014.
“We put a lot of resources into mitigating this statewide, and we’ve had a pretty successful track record for 30 years,” Burfitt said.