Saturday, January 31, 2009

Alien Invaders, Part II

Our most recent aliens are not actually at my house yet (and hopefully never). They were discovered in Worcester, which is about an hour west of us. It hasn't been long since they were first spotted in August of last year though the estimate is that they have been in the area for at least five years based on how far it has traveled.

Imagine huge black spotted beetles about 3-4 cm long. Now imagine their young have a taste for the inside of your maples trees and you live in New England, the land of beautiful fall foliage and maple syrup. It is not a pretty thing to think about.

(Photo: Donald Duerr, USDA Forest Service,

These beetles bore into maples slowly killing them over several years. There are other trees that are susceptible - birch, willow, elm and horse chestnut - but Worcester's trees are predominantly maple.

There have been previous infestations in isolated spots around the country. It gets here from China. Our love for imported goods is what brings it in since it hitches a ride on wooden material, like packing crates and pallets. In the US the control for this insect in the past (and for here) has been eradication.

Luckily it is a lazy insect. It doesn't fly far. Usually it is a home body and sticks to the same area it was born in. It doesn't travel more than a mile and a half and the adults don't over winter. They die after the first frost, though their eggs live on. The most important thing for us to do is not to transport it out of its area via plants, firewood and the like. Currently they have a delineated area that is being quarantined.

The second thing is to find all of the infected trees. Then after the first hard frost (so the adults don't decide to travel more) cut them down and burn them inside the infected area. Infected trees have dig spots in them which can be identified. This is where the adults lay their eggs.

It is a very scary infestation. Much scarier than the one I talked about yesterday. Though it has been eradicated from the US during other infestations, we have never had an infestation found before that is so close to heavily forested areas. The possibility for this getting out of control is much greater than in the past, so if you live in Massachusetts, especially near the Worcester area, please learn how to spot it and what it looks like and take a look around your yard. In the beetle's native area, the trees are all pretty resistant to the beetle. In the US this is not the case.

The photo above is of a dead beetle. It actually has little blue socks when it is alive. If you want to see lots of photos so you can identify it and its dig spots, the UMass Extension has a nice PDF (warning the file is large). It also tells you how to report a find of the beetle on the last slide.


  1. In the past few years, I have lost a weeping birch and a peach tree to borers. Last year I lost a flowering dogwood to ??? It's always sad to lose a precious tree.

  2. There are a lot of nasty invaders around these days, and for those who are squeamish about bugs, they aren't likely to even notice something new in the garden until it's too late. I hope these get eradicated before they start eradicating plants in earnest.

  3. You hit the point of the problem perfectly on the head! It is, indeed, our infatuation with imported goods that, once again, is getting us into trouble. Buy it local, know where the source product comes from (local!) and cut the head off of this terrible monster!!

  4. Daphne,
    Thanks for the information. I shudder to think what an infestation of these uglies would do here in Vermont, as well as all of New England. I was recently told of an infestation in Colorado, they have had significant damage from pine beetles (spanning 2 million acres) to their mature pine trees.

  5. What a beast! That's why I am trying to plant more natives in my garden and veer away from the exotics that are not adapted to my area. Bad bugs need natural predators to keep them in check.

  6. Annie's Granny, I know I would hate to lose my trees (well maybe the Norway Maples in the front would be ok). For Worcester is is a really problem, 81% of there trees are maple. I suppose if I lost that many I would have more sun and could grow more vegetables. Sun is sorely lacking in my yard. BTW I saw one of those peach borers for the first time this summer. They are huge.

    jodi, I happen to love seeing new insects(as long as they are outside, and not these nasty imports). When I see a new one in my garden, I try to figure out what it is. The holes they drill when they come out are very noticeable, but sometimes we just overlook things. It is too bad it took 5 years before anyone noticed them.

    shibaguyz, it is true. We are addicted to cheap imported goods. It's a bad habit that is hard to break.

  7. Liisa, I too shudder because it would take out most of our forests, habitat and maple syrup. I love maple syrup. I grew up in Colorado and remember when the pine beetles went through in the 70s. It can be very nasty. It took out whole hillsides of pine but healthy pines can repel the beetles (by putting out sap). Of course if there is a drought, the pine is already weak and can die. Or if it is infested by mistletoe as most of the ponderosa pines were where I grew up. The Asian longhorn will kill even healthy trees.

    perennialgardener, I should be planting more natives in my garden. I guess I did last year when I planted blueberries :> They grow wild in New England.