The Emerald Ash Borer hits Milwaukee
A couple of weeks ago The Milwaukee Journal-Sentinal reported on the invasion of the city by the Emerald Ash Borer (Agrilus planipennis). Here's a link to the story.
This invasive borer is going to wreak some serious havoc with the Ash (Fraxinus spp.) resource here in Brew City. Here is a link to the International information site for the Emerald Ash Borer (EAB).
There were few options given in the newspaper article. It seems there is also little time left to act or we face the certain loss of the resource. We can preemptively cut down the resource and lose it for the future, or we can use chemicals that will be injected directly into the tree. For the record there is no mention of any type of cultural option for prevention of the infestation on particular trees. Cultural practices can be very effective in maintaining tree health. Utilizing permaculture techniques may go a long way in doing that. The American Elm Bark Beetle (Hylurgopinus rufipes) is responsible for the Dutch Elm Disease epidemic on American Elm (Ulmus americana). The disease is a fungal infection that is introduced to the tree by the excrement of the beetle which lays eggs under the bark.
It has proven effective in combating the spread of Dutch Elm Disease to prune American Elms only in the dormant period. In Milwaukee the dormant period is roughly mid-October to mid-March. It is clear that this practice does not eliminate the chance of infection. However, it has proven to be an important tool in the fight to stop the spread of the infection. There are other options also available to homeowners and businesses alike that don't involve pesticides. The options are a lot more holistic and work well when implemented together. One of my clients has a mature Burr Oak that is realizing the benefits of being part of a hugelkultur. ere is a link.
The use of permaculture principles is an option. Here is a link that can help describe the principles. The main consideration is the cycle of life and the utilization of the materials produced.
The use of pesticides can have a devastating impact on the ecosystems that are already struggling with the climactic changes brought on by global warming. Within the information about the pesticides that could be used to "control" the insects it is stated that Imidacloprid is one of the insecticides most commonly used. This insecticide is injected either into the soil in the root zone of the tree or directly into the trunk of the tree. The insecticide is taken up by the tree and when the insect ingests the tree, it dies. Although the website suggests that the risks to mammals are less than the risk to insects, it is clear that the chemical is a poison. In a recent Harvard study there is a strong correlation found between Imidacloprid use and colony collapse disorder in Honey Bees. Here is a link to a story about that study.
There is the option to use permaculture techniques to bolster the root zones of our tree resource. The trees are able to survive in so many stressful situations. Ash especially get the hard to grow in places like planter-boxes in suburban parking lots and sidewalks. These boxes can be nutrient poor. Many Ash trees are stressed at this time in Milwaukee due to the drought. There are many situations in which trees will give off stress-related phermones that attract insects. But there are also things we can do to reduce the stress on the trees.
We can take the grass out of production. We can use mulch and wood chips and compost to naturally fertilize and innoculate the root zone with beneficial fungi. We can use permaculture techniques to grow food and flowers in harmony with the trees. This will attract birds, bees and mammals that will in turn benefit the whole system. The arrival of the Emerald Ash Borer to Milwaukee is an opportunity to learn. If we want to keep our Ash resource for future generations, we may need to adapt to a changing climate. We need to explore cultural practices that can make an appreciable difference in preserving the resource. Clearly there is room for the chemical option once all else has failed. There is long way to go before I will be convinced that all else has indeed failed. There will be more to be said on this topic for sure, but for now it is appropriate to not be hasty. We will see what works and what doesn't. For now I take solace in knowing that even though the insect can be devastating three to five percent of the trees usually survive. As with the Elms, there will still be Ash trees. We just have to learn how to take care of them.
Here is a picture of my clients' hugelkultur.
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