August 13, 2022

Public Advisory from the Essex Tree Warden

The emerald ash borer adult beetle

The emerald ash borer adult beetle

The Connecticut Agricultural Experiment Station (CAES) is advising all residents of Connecticut that the emerald ash borer (EAB – agrilus planipennis) has quickly spread throughout Connecticut, making it now part of the federal EAB quarantine. Residents should be aware of this invasive insect and the threat it poses to all ash trees in our community.

The emerald ash borer is a beetle in the buprestid family that is native to Asia.  First discovered in 2002 in Detroit, it has rapidly spread across the US.  It may have first been introduced via wood-packing materials and continued spreading by humans in everything from firewood to rustic crafts.  Because the beetle is a strong flier, it  can spread on its own as well.

CAES describes the adult beetle as metallic green, about ½ inch long. It feeds exclusively on ash trees in the genus Fraxinus.  Tiny, flat, round 1mm long eggs are laid in the bark crevices.  Seven to 10 days later, the eggs hatch and the young larvae begin to feed on the tree’s conducting tissues.  As they feed and grow, the larvae create distinctive tightly-winding ‘serpentine galleries.’  This process quickly stresses and girdles the ash tree.

The emerald ash borer larva

The emerald ash borer larva

During the winter the mature larvae remain in a pupal chamber and pupate in the spring.  The adult beetles emerge by chewing a distinctive 4mm wide D-shaped exit hole.  The adults feed on the margins of the ash foliage prior to mating.  The lifespan is 4-5 weeks, during which time a single female may lay upwards of 60 eggs.

It has been difficult to survey for this pest because of its small size. Some monitoring and trapping methods have been used including purple panel traps. Another is  “biosurveillance” by scientists and volunteers who monitor the nests of a native wasp that specifically hunts buprestids, including EAB.

The overall effect of the ash borer is the decline of the ash trees.  Infected trees are  attacked by woodpeckers who strip bark while trying to reach the larvae.  The eventual loss of ash trees will have ripple effects on other organisms including butterflies and moths as well as wood duck, bob white, purple finch, pine grosbeak and fox squirrels all of which eat the seeds of the ash tree.

To identify an ash tree look for compound leaves and opposite branching.  Ash trees have diamond patterned bark which provides distinct crevices.  Ash seeds are winged, resembling maple pinwheels.  Ash trees do not produce berries.  The ash tree is valued for its combination of strength and flexibility.  It is used as shovel handles, baseball bats and in construction of guitar bodies.

The D-shaped exit holes of the emerald ash borer in an ash tree

The D-shaped exit holes of the emerald ash borer in an ash tree

According to the Connecticut Department of Energy and Environmental Protection, Connecticut is seeking to slow the spread of EAB by a quarantine to keep any infested ash materials from leaving Ct. and going to an area that is not infested.  The quarantine targets ash logs, hardwood firewood, yard waste and ash nursery stock.  Also, a ban on the importation of firewood into Ct. through New York or Massachusetts – unless it is properly certified as not coming from an infested area – has been instituted.

Individuals can help in the following ways:

  1. Know what an ash tree looks like and monitor the ash trees you are responsible for.
  2. Act quickly to report any ash trees that are declining and may pose a threat to people or structures.
  3. Be careful when moving firewood or young trees. Use locally obtained firewood.
  4. Notify the Tree Warden of concerns about street or park trees.

Private trees are the responsibility of the property owner.  DEEP encourages owners of ash trees to contact an arborist for further help in monitoring the status of your trees and to use the resources available at the CT Agricultural Experiment Station and DEEP.

According to the CAES, ash trees that are still healthy can be treated for and protected against EAB using commercially available pesticides.  Ash trees that are not treated will eventually die and should be preemptively removed.  Please contact your local arborist for expert advice.

 

The above information has been provided by the Connecticut Agricultural Experiment Station and the Department of Energy & Environmental Protection. For more information go to the following websites: www.emeraldashborer.info or www.ct.gov/deep or www.ct.gov/caes. Contact Augie Pampel, Essex Tree Warden at: augiepampel@att.net with any questions or concerns.