Invaders

On Wednesday I attended another chapter meeting for my master naturalist group. This time we had a DNR entomologist speak about Emerald Ash Borers and other invading species. She told us house flies were invasive. Mosquitoes are not. Even bacteria and viruses can be invasive - oak wilt for one. The problem with invasive species started on this continent when people from other continents came over. They brought all kinds of creatures with them; some on purpose and others accidentally. The problem is worse now with our global economy. Some things are easy to tell where they came from. Dutch elm disease is an example. Emerald ash borers took a while. No one noticed the little bugs at first. The damage emerald ash borers do to trees is not visible for a long time unless you peel back the bark. Experts suspect the ash borers came via wood crate. Crates are supposed to be fumigated and bark free but people do try to cut corners to make a living and we don't have inspectors at every port of call. The bark on two pieces of wood can be nailed together so they don't show. We have other ash borers here in Minnesota but they have predators that keep them in check. We were told to be ready to see streets devastated like we did in the 1970's when Dutch elm took all the elm. It's because of Dutch elm that we have so many ash trees on our boulevards. The wood from all these fallen ash trees is still good to use once the bark is off. If some enterprising mind could come up with a use for tons and tons of ash wood, a fortune could be made. Ash is a very attractive wood with markings much like oak.