Scientists from the Connecticut Agricultural Experiment Station finally have proof that the emerald ash borer beetle, which can kill stressed trees within two years and healthier trees within four years, is starting to kill trees in New Haven County.
Last month, the bright-green beetle was located in an underground wasp hive in Prospect, as part of a biosurveillance project.
Another one turned up in a nearby trap, one of about 540 placed statewide by the University of Connecticut to monitor possible insect migrants from New York state and Massachusetts, where firewood is quarantined in an attempt to stop the spread of the beetle.
But now, the ash borer has been found in two trees in Naugatuck, as well as traps in Bethany and Beacon Falls, said Claire E. Rutledge, an entomologist at the Agricultural Experiment Station.
Rutledge said that in Michigan, where the ash borer has been at work for about 15 years, up to 97 percent of ash trees are now dead. "I think our best bet at this point is to slow the spread and manage it," she said.
Various varieties of hardwood ash trees make up between 4 percent and 15 percent of Connecticut's forests, with higher amounts in rich, loamy woodlands in Litchfield County and the Naugatuck State Forest, and fewer along the sandy coast.
An estimated 41,000 ash trees are located along streets in cities and towns, where they replaced elm trees after the fatal Dutch Elm blight of the mid-20th century denuded cityscapes. The wood burns hot and clean and is famously used for baseball bats.
The iridescent-green ash borers have been hitchhiking on wood piles.
"Detection is really hard, but firewood seems to be the most likely route," Rutledge said. "Someone probably brought firewood into their backyard for their furnace. That's why we say, `Buy local, burn local.' "
Louis A. Magnarelli, director of the station, had plans to announce quarantine procedures that, while largely voluntary, will require landscapers, nurseries and other firewood sellers to prove they are selling wood that has been kiln-dried, seasoned or fumigated. The borer only infests living trees.
Municipal officials and homeowners will have to consider applying insecticide to the roots or have it injected into the trunks of landmark trees they want protected from the ash borer.
"We're not quite sure of the scope of this infestation," Magnarelli told state lawmakers last week. On Wednesday at the Prospect Fire Station, he was scheduled to officially declare the emergency and announce quarantine procedures that mirror federal requirements.
"This means raw materials within New Haven County will not be able to leave New Haven County without a permit and without oversight on our part," Magnarelli said.
Magnarelli last week told the legislative Regulations Review Committee to expect a set of new emergency regulations for a vote early this month.
"If the problem extends into urban areas, we're talking about power lines, we're talking about cars and people's houses in those particular areas as well," said Magnarelli. "If we can find a way to slow it down, which we're going to try to do, it's great. It's not as dangerous as the Asian longhorn beetle, another major pest that's in the Worcester area of Massachusetts, but it certainly warrants our full attention at this point."
Christopher Martin, director of forestry for the state Department of Energy and Environmental Protection, said that the emergency declaration will be combined with Gov. Dannel P. Malloy's recent announcement of emergency firewood regulations requiring origin confirmation of all wood moving around the state.
If Connecticut doesn't set up a New Haven County quarantine, the U.S. Department of Agriculture could declare the state an isolation zone, which would have a more adverse impact on the economy.
Owners of infected trees will eventually be asked to cut them down, since there is no funding for removal.
Richard Cowles, another experiment station entomologist, said Wednesday that inoculating trees is easier and less expensive than cutting them down. He said systemic insecticides, available at garden stores, can be mixed with water and poured around trees by homeowners.