Asian longhorned beetles

Q. I heard that the Asian longhorned beetle was found in Ohio. I’ve never heard of it. What is it and why are people worried about it?

Jerry from Girard

A. The Asian longhorned beetle recently was found in Clermont County near Cincinnati. There already was a quarantined area, but more were found outside of that area.

The ALB is an invasive insect from China and Korea and has no natural enemies in North America. Adult ALBs are large, shiny black insects measuring 1 to 1 Ω inches long, not including antennae, with random white spots. This is a huge insect. Their white-banded antennae can be as long as the body itself on females and almost twice the body length on the male beetles. These characteristics give the insect its name. It was first found in the United States in 1996 in Brooklyn, N.Y., and first identified in Ohio in 2011.

This is different than the invasive, tree-killing insect you may have heard of in our area – the emerald ash borer (EAB). The EAB arrived in Michigan in 2002 and in Ohio in 2003. It also is native to Asia and infests and kills ash trees. Since its arrival, this pest has killed hundreds of millions of native ash trees in North America and is found in all 88 counties of Ohio.

The ALB has the potential to do even worse damage to forests and landscapes than the EAB because the ALB infests more than one tree species, including alders, birches, poplars, willows, and more – 12 tree genera in all. It shows a particular liking for maples. Fortunately, the ALB has not established itself yet as the emerald ash borer has. Thus far, it has not been found in Northeast Ohio.

The ALB larvae kill young and mature trees by tunneling within the trunk and branches, disrupting sap flow, weakening and eventually killing the tree. After the larvae pupate, adult ALBs emerge from a characteristic round hole. No chemical or biological control methods are currently possible. The only tool to control this pest is the removal of infested trees and all adjacent trees.

The best defense against the ALB is early detection. With the leaves gone from deciduous trees, this is a great time to inspect trees and look for signs and symptoms of the ALB. This time of the year you will not see any adult beetles, but their exit holes will be easier to spot. The holes are perfectly round, about the diameter of a pencil and sometimes with frass (insect poop) emerging from the hole. There may also be limb breakage at points where larval activity has weakened branches. If you see any signs or symptoms of the ALB, contact your OSU Extension Office.

For more information, visit http://go.osu.edu/evenmoreALB.

Today’s answer is provided by David Sprague, OSU Extension master gardener volunteer. Winter hours for the Plant and Pest Diagnostic Clinic vary. Submit questions by calling 330-533-5538 or drop samples off at the Extension Office in Canfield.