Insect Likely to be Present in Norfolk Already
Loss of All Local Ash Trees Expected

By Lindsey Pizzica Rotolo

The Connecticut Agricultural Experiment Station issued a press release last month that the emerald ash borer (EAB) beetle population is rapidly expanding throughout the state.

The original Connecticut infestation of the invasive Chinese beetle began in 2012 in New Haven County, but has moved quickly through the border counties of Fairfield, Hartford, Litchfield and Middlesex. While infestations of the beetle are not currently present in Norfolk, they have been detected in Thomaston, Litchfield, Torrington and New Hartford this year.

Dr. Gale E. Ridge, who works in the Department of Entomology at the Connecticut Agricultural Experiment Station, warns that while Norfolk’s ash trees are seemingly unaffected, the beetle is likely to be here in town and there are steps homeowners can take to prevent the massive devastation of which these beetles are capable.

“There is a two-part systemic insecticide treatment that homeowners can employ to prevent EAB from flourishing,” Ridge advises. The first step is to spread granular Dinotefuran, a soil treatment, in a 20-foot ring from the trunks outward of ash trees before a rainstorm during the summer months. The second step is to treat the trees again in early April and late April using the same technique, but with Imidacloprid, another insecticide.

Ridge warns that if you have large ash trees on your property (20 inches or more in circumference), you should hire a tree professional or arborist to perform injections. Ridge warns that, “Left untreated, your ash trees will die. There is no question.”

While ash trees make up a relatively small percentage of our forests, just 4–15 percent according to the Connecticut Department of Energy and Environmental Protection (DEEP), EAB’s destruction of them is fast and furious. Once a tree is infested with the beetle, the tree dies within two to three years. There are no exceptions.

The metallic green beetles are small, less than half an inch in length, but highly destructive. Adults emerge from within ash trees in June, and they continue to surface for about five weeks. The females lay their eggs (up to 100 at a time) on the bark a week or two after emerging. Those eggs hatch within 7–10 days and the larvae move into the tree, where they remain for as long as two years, feeding the entire time.

The state is taking the situation seriously. Residents may have noticed the presence of bright purple, geometric insect traps around the county this past year. These traps, called Barney traps, are in place for the sole purpose of monitoring EAB populations. Male beetles are attracted to the color purple and the sexual pheromones applied to the sticky surface, so the traps have proved highly effective for data collection.

The Connecticut Agricultural Experiment Station is taking a more proactive approach. They have used a native wasp, the smoky winged bandit, to combat EAB populations. These wasps capture the beetles in the trees, paralyze them and bring them down to holes in the dirt which they have excavated. The wasps bury their prey with an egg laid on each beetle. When the eggs hatch, the baby wasps feed on the beetles, eventually killing them.

The station has also quarantined firewood in the state’s western counties, as one of the main ways EAB is spread is through infested ash firewood. DEEP has also limited the movement of all hardwood firewood throughout the state, but the state doesn’t have jurisdiction over interstate movement of firewood. That responsibility falls on the United States Department of Agriculture Animal & Plant Health Inspection Service (USDA APHIS).

Perhaps the only weak spot in EAB is that they can’t survive temperatures less than 15 below zero. Although the beetles possess an amazing survival technique of purging their guts and folding in half to withstand long periods of frigid temperatures, U.S. Forest Service biologists were delighted to find that 80 percent of the ash borers in Minnesota died this winter when the thermometer got down to minus 20 degrees Fahrenheit. The bad news is, the 20 percent who survived have already multiplied to catastrophic levels.

Star Childs, president of Great Mountain Forest, finds it all too convenient that EAB was first found in the Michigan port of Detroit, literally in the heart of the United Statesí ash-rich forest range.

“The rapid spread of the insects east and west has created a liquidation harvesting pressure on ash timber across the ash timber regions in advance of their inevitable infestation, which was probably the intention of the Chinese furniture manufacturing industry all along—to essentially cause a flood on the market with cheap and readily available ash logs for export to China. The Chinese, of course, have no ash shipment quarantine since the bug is indigenous to there in the first place.”

Conspiracy theory or not, the vast majority of cheap furniture for sale at big box stores in the U.S. is made in China from U.S.-sourced ash wood.

If you have ash trees on your property, contact your local tree professional or arborist. For a quick identification, ash trees have light gray bark with deep, regular grooves and opposite branching. The leaves are compound, and the oval leaflets are opposing (meaning the leaves are directly across from one another on stems). For more information about treatment, go to www.ncipmc.org and enter “Insecticide Options for Protecting Ash Trees from Emerald Ash Borer.”