Understanding A Threat To The Region's Ash Trees

Newtown is among a growing number of towns in recent years infested with the emerald ash borer, “a destructive insect responsible for the death and decline” of ash trees throughout the country, according to the Connecticut Agricultural Experiment Station. The ash borer was detected in Newtown in 2012-13. The damaging insect has now been detected in a total of 39 towns, the most recent being Bridgeport just last week.

Land Use Director George Benson is aware of the pest, and recommends that residents with concerns contact the experiment station at 203-974-8474 or CAES.StateEntomologist@ct.gov.

“Unfortunately, we are now seeing a lot of dead and dying ash in New Haven County and more ash trees will die as a result of this expanding infestation,” State Entomologist Kirby C. Stafford III said through a press release. Infested trees can be treated with systemic insecticides to protect them.

Untreated ash trees will be lost and can die within two to three years.

Monitoring the ground-nesting, native wasp (Cerceris fumipennis) that hunts many wood-boring beetles, including the emerald ash borer, can help detect the insect’s presence. The wasp is an effective “biological surveillance” survey tool and does not sting people or pets, according to Dr Claire E. Rutledge, who runs the extension station survey program.

According to Conservation Commission Chair Ann Astarita, “The fact that the wasps are finding [ash borers] might work in our favor and hopefully delay the spread of the [ash borer] and the death of our ash trees.”

In addition, purple detection traps hung in trees have been set across several counties by members of the University of Connecticut Cooperative Extension System.

The Connecticut Agricultural Experiment Station announced in mid-July that the emerald ash borer (Agrilus planipennis) infestation, largely centered in New Haven County, has rapidly expanded into Fairfield, Hartford, Litchfield, and Middlesex Counties. The other towns where the beetle has been detected this year are: Ansonia, Branford, Bristol, Clinton, Cromwell, Derby, Durham, Litchfield, Meriden, New Haven, North Haven, Orange, Plainville, Rocky Hill, Seymour, Shelton, Thomaston, Trumbull, Wallingford, West Haven, Wolcott, Woodbridge, and Woodbury.

In addition to Newtown, the insects were previously found in Beacon Falls, Bethany, Cheshire, Hamden, Middlebury, Naugatuck, North Branford, Oxford, Prospect, Sherman, Southbury, Southington, Waterbury and Watertown in 2012 or 2013. Additional detections are anticipated.

The emerald ash borer is a destructive insect and has been responsible for the death and decline of tens of millions of ash trees from Colorado and the Midwest to New England and south to Georgia.

Ash makes up about four to 15 percent of Connecticut’s forests and represents about two to three percent of the urban trees in many communities.

According to the Department of Energy and Environmental Protection (DEEP), “The emerald ash borer is a small, green beetle that belongs to a large family of beetles known as the buprestids, or metallic wood boring beetles. The description is apt, as many of the adult buprestids are indeed glossy, appearing as if their wing covers are made of polished metal. The emerald ash borer, with its green, iridescent wing covers, fits right in. Adult emerald ash borers are between 0.3 to 0.55 inches in length — small by most standards but large compared to other buprestids — and relatively slender.”

Also according to the DEEP, the ash borer feeds on a portion of the inner tree bark that normally allows nutrients to travel to other parts of the tree. Without it, “other parts of the tree become cut off from their food source. This effectively girdles the tree and it dies,” the site states.


Know The Signs

As explained on the DEEP site, “The first symptom that an ash tree is infested with [ash borers] is often thinning and dieback in the tree’s upper canopy. ... A definite sign of the [ash borer] is the presence of a D-shaped exit hole in the bark of an ash tree.”

Other symptoms include S-shaped tunnels on surface under the bark, sprout growth at the tree base, unusual activity by woodpeckers, die-back on the top third of the tree, and vertical splits in the bark.

If a tree has two or more symptoms, report signs to CT Agricultural Experiment Station by sending digital photos to CAES.StateEntomologist@ct.gov. Additional information can be found on the www.emeraldashborer.info website.

What can residents do? The DEEP website offers the following advice:

*Be aware of the possibility of the presence of this insect in Connecticut, including becoming familiar with the signs of its presence on ash trees;

*Report any suspected finds to the CT Agricultural Experiment Station; and

*Be especially careful when moving any firewood or young trees.

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