Article republished with permission from the American Forest Foundation.
Originally posted at My Alabama Woods
In the last 20 years, about one new species of beetle has landed on North American shores each year, imported from other parts of the world. The arrivals come mostly in wood pallets and other packing materials. Every time a giant cargo ship arrives in a port, loaded with huge containers that transfer to trucks and trains, it could be bringing in a new pest. World trade is so huge, it’s impossible to inspect all goods for tiny stowaways.
And that’s just beetles. Other insects can kill trees, too. And it’s not only imports, but also native insects that attack woods. So can fungi and diseases caused by other pathogens.
It’s appealing to just let your trees take care of themselves, but in the case of invasive species, they may not be able to; trees have little protection against bugs from overseas. Even native pests can overwhelm trees’ natural defenses. When trees die, that can affect the animals that live in them and the plants that grow beneath them.
(Photo by James H. Miller, USDA Forest Service, Bugwood.org)
People with woods aren’t helpless. You can make your woods less hospitable to insects and disease. And when the little pests do show up, there are often early warning signs. With WoodsCamp you can get introduced to a local expert like a forester or Cooperative Extension office, you may be able to identify the culprits and fight them off with pesticides, chainsaws, fire, or other tools.
My Invasive Species Checklist
- Keep an eye out for changes in your woods. A spot of yellow or brown, or some thinning needles, might be the effects of natural shading on lower limbs—or it might be a disease or insect that is about to spread to other trees.
- Stay informed about threats in your area. If traps are available for problematic insects in your area, use these to find out how common the insects are.
- Monitor for pests and signs of disease every month or two during the growing season. Take a walk in the woods and check trees on the trunk, limbs, twigs, under peeling bark, and leaves—the most likely places to find injuries. You don’t have to check every single tree. Keep your eye open for things that look out of the ordinary.
- Call your local Cooperative Extension office or another expert if you see something suspicious.
- Pay attention to the normal insects around you. Most aren’t harmful and many even help by eating pests. Just as different plants bloom at different times, different insects have their seasons. If you notice when certain moths appear in the spring, or when the first butterflies of a particular type appear in the garden, it could help you keep track of the normal shifts in insect life through the year.
What To Do If I Suspect An Outbreak
Injury from one type of problem can look similar to another, to the untrained eye. It may be hard to tell at a glance whether you’re dealing with damage from drought, an insect borer, or a fungal canker. Collecting samples of tree damage and any associated pests is important in accurately identifying the problem, which may have more than one cause.
Take pictures and notes on your trees’ symptoms, and talk to local forest experts for help in identifying the causes. Often pictures are enough for an expert to identify the problem. If you discover an insect that you suspect might be a danger to your trees, seal it in a container and store it in the freezer until you can deliver it to a proper authority.
How you respond to a pest depends on what exactly is causing the damage. You may need to use pesticides or cut down the affected trees. You may need to burn the affected trees or take out more trees to create a buffer zone. An expert can help you figure out what to do next.
Prevention Steps I Can Take
Keep my woods healthy
The best way to prevent disease and insect outbreaks is to keep your trees healthy. Just like people, trees can be stressed, which can make them more vulnerable to insects and disease. For example, when trees are attacked, sometimes they can push out pests by moving large volumes of sap through their branches—but not if they’re too crowded or aren’t getting enough water. Like people, if they aren’t healthy, they can’t fight off minor infections.
Maintain a diverse woods
Once a tree is attacked, insects and pathogens can spread to neighbors. Many pests only attack a single species, so it’s useful to have a mix of trees in your woods. Also, keeping trees farther apart helps them stay healthy by getting the light, water, and soil nutrients they need—although it can also help weeds grow on the forest floor. An expert can help you figure out the best way to keep the trees in your woods happy and healthy.
Don't move firewood
Don’t move firewood long distances. Tree-killing pests hitch rides on wood, even wood that looks fine. A pest could be lurking—all it takes is a couple of insect eggs or microscopic fungal spores. As a rule of thumb, try to get firewood from less than 10 miles away. Some states have laws against moving firewood long distances.
Use Pesticides Appropriately
Pesticides are part of managing pests to cause diseases. Use them correctly to avoid disrupting natural insect communities. Insect predators and parasites—the good bugs you want in your woods—thrive when they have a lot of insects to choose from.
Want more information?
Or you can learn more on your own
- Alabama Invasive Plant Council: http://www.se-eppc.org/alabama
- Alabama’s 10 Worst Invasive Weeds: http://www.se-eppc.org/pubs/alabama.pdf
- A Field Guides for the Identification of Invasive Plants in Southern Forests: http://www.forestpests.org/pdf/A%20Field%20Guide%20for%20the%20Identification%20of%20Invasive%20Plants%20in%20Southern%20Forests.pdf
- A Management Guide for Invasive Plants in Southern Forests: http://www.forestpests.org/pdf/A%20Management%20Guide%20for%20Invasive%20Plants%20in%20Southern%20Forests.pdf
- Bark Beetles of Southern Pines – Identification and Control: http://www.barkbeetles.org/general/idcntrl.html
- Insects and Diseases of Trees in the South: http://wiki.bugwood.org/Archive:South
- Integrated Pest Management in Southern Pine Forests: http://www.barkbeetles.org/spb/IPMinSPF/IPMIndex.html
- State Resources for Alabama from the National Invasive Species Information center: https://www.invasivespeciesinfo.gov/unitedstates/al.shtml
- Alabama State-listed Noxious Weeds: http://plants.usda.gov/java/noxious?rptType=State&statefips=01
- Find out about pests, weeds and diseases in your region: mylandplan.org/pests
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