April - June, 2007
Firewood Pests?
Most of us wouldn't pick up hitchhikers along the road, but many of us unwittingly take them camping with us. Tree-killing pests such as emerald ash borers, Asian longhorned beetles and gypsy moths can hide in the wood we bring for campfires. It's easy to reduce the spread of these hitchhiking pests. Here's how.
Missouri has always had its share of forest pests. Historically, these native insects and diseases posed little threat to our healthy forests because for thousands of years our native trees and other plants have evolved alongside them. Whenever a native pest developed a new method to attack, our forests responded by evolving new defense mechanisms. Non-native pests throw off this natural balance by bringing with them new methods of attack unfamiliar to our native trees and plants. Because our forests have not had time to evolve adequate defenses, they can become easy prey for exotic invaders. Take for instance the emerald ash borer. This metallic green beetle probably entered southeast Michigan as an unwanted hitchhiker in wooden packing materials used to ship goods from its native home in China and eastern Asia. The wormlike larvae of this tiny but destructive insect tunnel through native ash trees, eventually killing each tree they infest. To date, emerald ash borers have killed more than 15 million ash trees in Michigan and hundreds of thousands more in Indiana, Ohio and Canada. They haven't made their way to Missouri, yet, but they appeared near Chicago in June of 2006.
One way to keep emerald ash borers and other destructive pests out of Missouri's healthy forests is to avoid transporting firewood long distances. How far is too far? There isn't an easy answer. Moving firewood a few miles from your farm to your home should never be a problem. And at this time, if you avoid transporting firewood across state lines, you should be okay. However, as economies and trade routes become more globalized, opportunities for exotic pests to hitchhike to Missouri increase. If these pests gain a toehold in Missouri, simply moving firewood from one end of the state to the other could cause problems. In all instances, the best policy is to obtain firewood from a local source. If you brought firewood in from out of state, burn all of it as soon as possible. This will kill any pests that could be hiding in the wood.
Another thing we can do to keep Missouri's forests healthy is to watch out for exotic hitchhikers. Keep in mind that Missouri has its share of native pests, so finding a bug tunneling through your firewood isn't necessarily cause for alarm. Learning to separate the benign native bugs from the destructive exotic bugs is key to early detection of a potential problem.
Early detection is useful only when the problem is contained and eradicated. To help with this effort contact the Missouri Departments of Conservation or Agriculture should you find a suspect insect. Collect a sample by trapping the insect in a zippered plastic bag. Place the bag in the freezer for several days to kill the insect then mail the sample in a sturdy container (35mm film canisters work well) to the address below. Be sure to include your contact information and the date and location where you captured the sample.
Rob Lawrence
Forest Entomologist, Missouri
Department of Conservation
1110 S. College Ave.
Columbia, MO 65201
573/882-9909 ext. 3303
robert.lawrence@mdc.mo.gov