Emerald Ash Borer: Beware of this pest

Friday, 10 June 2011 13:27

(Editor’s Note: The Connecticut Agricultural Experiment Station, state DEP Division of Forestry and the University of Connecticut Cooperative Extension Service, along with its federal partners, the USDA Forest Service and the USDA Animal and Plant Health Inspection Service (APHIS), have put together the following short summary on the Emerald Ash Borer, considered a major concern for municipalities.)

The emerald ash borer is a non-native insect with the potential to have a devastating effect on the ash trees of Connecticut. This insect, a bark-boring beetle, is perilously close to the state, with a major outbreak outside of Kingston, N.Y., just 25 miles west of the state line. This insect can be easily moved in firewood and through other means. Because of that, we are encouraging greater awareness of EAB. We hope to reduce the likelihood of its inadvertent spread. We also want to help prepare people for dealing with the insect should it be found in Connecticut.

EAB is a small, bright-green beetle that does its damage as a larva, feeding on the inner bark of ash trees. Its numbers build rapidly in an infestation, and these numbers will kill mature trees within three to five years. Its life cycle is between one and two years long, with the adults most likely to be found in June or July. Since the adult is small and only lives outside of the tree for a few weeks, the most likely way that the beetle will be found will be through the damage it causes trees.

Ash trees are a small but important component of our woodlands and urban forests. The tree is a primary food source and provides habitat for a wide range of native insects, birds and mammals; it contributes to the diversity of the forest and is a key component in the spectacular display of leaf color that is so much a part of the experience of fall in Connecticut.

The people with the most at stake are woodland owners, residential and commercial property owners and municipalities. For woodland owners, ash can be a valuable timber tree as well as an important part of the forest ecosystem. Municipalities likewise face significant economic impacts. For example, if a community has 10,000 street trees and 5% of these are ash trees, as these ash trees die, this means 500 more trees that need to be removed.

The first and most important suggestion is to not overreact. Until EAB is found nearby, there is not much that one can do with regards to EAB, other than becoming informed about the beetle and about the nature and extent of the local ash resource.

Woodland owners, private property owners such as homeowners, and municipalities are all likely to look at EAB differently. There are numerous good sources of information regarding EAB, many geared towards these variations in perspective. The Web site www.emeraldashborer.info is an excellent clearinghouse for information. The State of Connecticut has also developed excellent resource materials that can be found online through the DEP Division of Forestry, www.ct.gov/dep/forestry, the Connecticut Agricultural Experiment Station, www.ct.gov/caes and the University of Connecticut Cooperative Extension Service, www.extension.uconn.edu/pages/environment.html.

Individuals with direct concerns about ash trees should also consider contacting a professional with the expertise appropriate to their need, such as an arborist or a forester. Engaging individuals without these credentials can be damaging — not just legally, but also economically and environmentally, as non-credentialed individuals will not have the proven skills and knowledge as shown by the license or certification.

Anyone who suspects that they have found the insect or an infested tree is strongly encouraged to contact the State Entomologist at CAES ( This e-mail address is being protected from spambots. You need JavaScript enabled to view it or 203-974-8474). Take and send digital pictures, but do not move the wood or the insect! That will only risk spreading the infestation further.

The presence of the beetle does not require the removal of the trees — ultimately, that will be a decision to be made by the property owner. In the case of important landscape trees, treatments do exist that can kill beetles in a tree and prevent further infestation. A discussion of these various treatments is available on the emeraldashborer.info.

Should EAB be found in Connecticut, it is very likely that the state will impose a quarantine around the infested area. The purpose of this quarantine will be to help limit the spread of the beetle through the movement of firewood, logs, yard waste or infested nursery stock.

In advance of an infestation, perhaps the most helpful steps for members of the general public are those that reduce the movement of raw wood over long distances. In particular, firewood should be sawed, purchased and used locally, so as to limit the opportunity for EAB and other pests to hitch a ride within the firewood pile.