Pest Alert: Walnut Twig Beetle & Asian Longhorned Beetle


State Taking Measures Against Walnut Twig Beetle and Asian Longhorned Beetle; Officials Confirm
Thousand Cankers Disease for First Time in Ohio

REYNOLDSBURG, Ohio (August 12, 2013) ‐ In an effort to protect the trees of Ohio, the Ohio Department
of Agriculture (ODA) is encouraging Ohio citizens to check their trees for signs of the Walnut Twig Beetle
and Asian Longhorned Beetle. Both of these tree pests have been detected in southwest Ohio and
threaten the health and viability of the state’s hardwood forests, as well as some of the state’s leading
industries. Signs and symptoms of both the Walnut Twig Beetle and Asian Longhorned Beetle are visible
in August.

The Walnut Twig Beetle is a small beetle known to carry a fungus that causes Thousand Cankers Disease
(TCD), which can kill walnut trees. TCD is caused when the Walnut Twig Beetles bore into the branches
and trunk tissue of walnut trees, thereby introducing the fungus. Repeated attacks by the insect lead to
multiple individual infections by the fungus and the tree eventually dies. There is no known treatment
for TCD. The disease was first found in Colorado in 2003 and has since been detected in 13 other states.
Walnut Twig Beetle was first confirmed in Ohio in late 2012 in traps set by Ohio Department of Natural
Resources Division of Forestry officials in Butler County. Additionally, scientists from the Ohio Plant
Diagnostic Network, a cooperative partnership between ODA and The Ohio State University, recently
isolated the TCD fungus from walnut branch samples from the Butler County area, marking the first time
TCD has been confirmed in Ohio.

ODA is in the process of expanding its TCD quarantine to include Butler County. ODA officials have also
been working to set Walnut Twig Beetle traps in portions of Butler, Hamilton and Warren counties to
monitor for any additional infestations of the beetle.

Landowners and homeowners are strongly encouraged to watch for signs of TCD on their walnut trees.
Symptoms of TCD vary, but commonly include thinning crowns, yellowing or wilted leaves in the crown
and limbs that died recently.

More Walnut Twig Beetle & Thousand Cankers Disease Information:
Asian_longhorned_beetleAsian Longhorned Beetles are large, shiny black insects measuring 1 to 1 ½ inches long, not including
antennae, with random white spots. Their white‐banded antennae can be as long as the body itself on
females and almost twice the body length on males. The invasive Asian Longhorned Beetle grows,
reproduces in and kills up to 13 genera of trees such as maple, birch, horse chestnut, poplar, willow,
elm, ash and buckeye.

Asian Longhorned Beetle was first confirmed in Ohio in 2011. The beetles were found to be infesting
trees in Tate Township in Clermont County. In addition to the Ohio infestation, the beetle is currently
found in parts of Massachusetts and New York, with eradication efforts succeeding in Illinois and New
Jersey. ODA continues to work with the United States Department of Agriculture Animal and Health
Inspection Service (USDA APHIS) and other partners to eradicate the Asian Longhorned Beetle from
Ohio. In an effort to detect and prevent future infestations of Asian Longhorned Beetle USDA APHIS has
declared the month of August as Tree Check Month, encouraging citizens to get out and check their
trees for signs of the beetle.

Signs of Asian Longhorned Beetle infestation include perfectly round exit holes (about 3/8 to 1/2 inch in
diameter) made by adult beetles when they emerge from trees; the pockmarks on tree trunks and
branches where female beetles deposit eggs; frass (wood shavings and saw dust) produced by larval
feeding and tunneling; early fall coloration of leaves or dead branches; and running sap produced by the
tree at the egg laying sites, or in response to larval tunneling. Infested trees may also snap or break
during high winds due to the wood being weakened by tunneling.

ODA encourages citizens to check their trees and be on the lookout for signs of these pests. To report
signs and symptoms on your trees, please contact ODA at 855‐252‐6450 or by email at . For more information go to

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