Beware of Bugs

Firewood and the Forest

Charlene Donahue, Forest Entomologist

Department of Conservation - Maine Forest Service

Ninety years ago the threat humans posed to the Maine forests was fire.  Woodsmen, hunters and fishermen left campfires burning.  Smokers threw matches or cigarettes on the ground. Brush was burned on dry windy days. People did not think a lot about fire and the effect their actions could have on the forest.  A huge campaign was undertaken to raise awareness of how people are often responsible for starting forest fires.  As far back as 1916 the Forest Service was soliciting help in protecting the forests and Smokey Bear just had his 60^th birthday celebrating his promotion of “Only You Can Prevent Forest Fires”.  Everyone knows about the dangers of being careless with fire in the woods.

Now there is a new threat to the forest.  Just like years ago it is something people were not aware of. It is a behavior that has been going on for eons and in the past there was nothing wrong with it.  But times have changed, the world has changed and now some of us need to change as well.  Once again the Forest Service is asking for the public’s help in protecting the forests.

What threatens our forest today? Something that has really only come to light in the twenty-first century - moving firewood.

Anyone who has camped or owns a camp has probably at one time or another brought firewood along on a trip.  You have firewood in the backyard, it’s dry, it doesn’t cost anything, you won’t have to stop along the way, so you bring it along. It has always been an acceptable practice, until now.

So what is the problem?  The problem is invasive insects that now are traveling with that firewood.  With global trade we also have global spread of insects. Unfortunately some of these insects “from away” find their new home very hospitable and they are destroying our tress and our forests.

One of the nastiest examples is the Emerald Ash Borer (EAB).  This is a metallic woodborer from Asia that kills any type of ash tree in North America. In Asia it is a minor pest of ash but the North American ash trees have no defenses against this insect.  The trees can die within as little as two years after attack by the beetles.  The EAB adult female lays her eggs on the bark of the tree.  The larvae hatch and feed beneath the bark creating tunnels that cut off the tree’s flow of food and water and eventually kill it.

EAB was first discovered in Michigan in 2002 and most recently in western New York in June 2009. During those seven years, EAB has been found in 11 other states, as well as Ontario and Quebec, Canada.  Millions of ash trees have died from attack by EAB and the concern that these species of trees will be lost is so great that seeds are being saved.

Another example of an invasive insect that threatens Maine forests is the Asian Longhorned Beetle (ALB). Like the emerald ash borer, it arrived from Asia in packing crates. This insect attacks a wide range of hardwood trees: especially maple and birch. The ALB was first found in cities – New York and its environs, Chicago and Toronto.  And just last summer ALB was found in Worcester, Massachusetts where it has been for 10 to 15 YEARS.  It is in some of the forested area as well as in city trees. Worcester, MA is less then 90 miles from the Maine border; less than two hours by car.  I wonder if anyone from Worcester has brought firewood to Maine in the last 10 years?

We do not always know when a harmful pest has moved into an area, and the ALB find in Worcester showed us once again how elusive invasive species can be.  And, we cannot always tell if firewood is infested with harmful insects.  They can be in, on or under the bark, or in the wood itself.  If we want to protect the health of our trees and forests, we need to change our habits. We need to leave our firewood at home.  We need to take the time to buy or gather firewood near where we burn it.

There are federal quarantines in place on invasive pests. These quarantines prohibit the movement of firewood out of KNOWN infested areas.  But what about problems that have not been identified yet? Do you know if there are invasive insects in your backyard?  There is no law at this time preventing the movement of firewood into Maine.  What we need is for people to change their habits. Just as 90 years ago people needed to be more careful with fire, today people also need to be more careful with firewood.

Change is not easy but neither is dealing with invasive insects.