Another Invasive Species Threatens from the West

Much of the news about invasive species this year has centered on the threat of zebra mussels to Candlewood Lake. But water bodies are not the only natural resource under attack from foreign invaders.

State environmental officials are now warning about the nearby presence of another invasive species. It is called the Emerald Ash Borer. And the pest is now in the Kingston, NY area — only about 25 miles from the northwest border of CT.

The Emerald Ash Borer is a small, bark-boring beetle that attacks and kills ash trees. Only about three percent of the trees in CT are ash, but they comprise as much as 20 percent of the stock of in the northwest corner of the state. 

The most common species of ash in CT is the white ash. Two other species are also native: the green or red ash, and the black ash. Despite its name, the mountain ash is not a true ash and does not attract the EAB pest.

The wood of the white ash is prized due to its combination of strength and flexibility, which makes it ideal for uses such as shovel handles and baseball bats as well as electric guitar bodies. Ash trees also play a key role in sustaining other native species, such as butterflies, moths, wood ducks and fox squirrels. 

Impacts other species

Aside from the loss of a native tree, environmental officials are also concerned about the rippling impact the loss would have on those species that rely on the tree, as well as the opportunity the loss would give to other invasive species to ‘fill the gap’ left by the loss.

The EAB is rapidly advancing. First discovered near Detroit in 2002, presumably arriving from Asia in woody packaging material, the pest has moved swiftly and is now found in 12 states.

Like the zebra mussel, the EAB is capable of advancing on its own — but human activity is believed to aid its spread. The movement of ash, in particular via firewood, ash logs, wood packaging material and nursery stock, is the most likely means of spreading the pest. 

Environmental officials in both NY and CT are now cooperating in an effort to track and hopefully slow the spread of the EAB. The most visible aspect of this early detection and monitoring effort is the appearance of purple, triangular-shaped boxes, which are now being deployed at tree top levels in eastern NY and western CT.

The purple boxes, which resemble box kites, are sticky traps that the U.S. Dept of Agriculture and the cooperating state agencies are using to pinpoint the spread of the pest.

They are already in place in Dutchess County, NY and Litchfield and northern Fairfield Counties in CT. 

Early warning

The traps use Manuka oil as a lure and a sticky material to cause the EAB to adhere to it. The sticky surface is not noxious. Other insects may get stuck on the trap, but the pheromone is designed to lure the EAB. Environmental officials emphasize the trap will not harm birds and other animals.

The traps are being deployed from May through August to correspond to the adult life stage of the EAB. If the traps detect the presence of the pest, environmental officials will likely quarantine the infested area to limit the spread of the pest through the movement of firewood, logs, yard waste or infested nursery stock. 

In areas not yet infected by the EAB, voluntary compliance with the protocols restricting its spread are the best means of containment. For the typical homeowner, voluntary compliance most often centers on the use of firewood, or more specifically, using only firewood that is produced locally to limit the opportunity for the pest to hitch a ride within the firewood pile.

The simple phrase — Don’t Move Firewood — is the best advice available.

Anyone who suspects they have found the EAB pest or an infected tree should contact the State Entomologist at the CT Agricultural Experiment Station at CAES.StateEntomologist@ct.gov or 203-974-8474. Be sure to take and e-mail digital pictures. Do not move the wood or the insect. Movement simply increases the risk of spreading the infestation further.

According to the environmental officials, the presence of the EAB does not always require the removal of the tree. In the case of important landscape trees, treatments exist that can kill the EAB in a tree and prevent further infestation.

Resource materials can be found online through the DEP Division of Forestry, the Connecticut Agricultural Experiment Station (CAES) and the University of Connecticut Cooperative Extension Service.