Few trees possess the elegance and iconic status held by elm trees. Unfortunately, these stately bastions of shade are vulnerable to a highly contagious disease, Dutch elm disease, which is capable of reducing them to a pile of wood chips. If you own one or more elm trees and would like to increase your knowledge of how to protect them, read on. This article will arm you with some vital information about Dutch elm disease.
The Cause
Chances are you're already aware of Dutch elm disease, as this pernicious disease has ravaged vast swathes of elm trees across the nation. Dutch elm disease is caused by a fungus that is, in turn, spread from tree to tree by a specific species of beetle—the elm bark beetle.
These beetles are naturally drawn to elm trees, beneath whose bark they like to lay deposits of their eggs. The fungus has no effect on the beetles themselves, nor on their larvae. When adolescent beetles hatch, they move off in search of another elm tree to colonize, unknowingly carrying the debilitating fungus along with them.
Symptoms
The first symptom to appear when a tree has been infected with Dutch elm disease are patches of yellow leaves. Such patches occur without any location or pattern specificity; they simply indicate the part of the tree the beetles have colonized. Dutch elm disease can be further confirmed by peeling away the bark from a young branch, then slicing it on the diagonal. If brown streaks are apparent in the underlying wood, this is a strong sign that your tree has contracted Dutch elm disease.
Treatment Options
If you have caught the disease in time, it may still be possible to stop it. This will first involve the application of an insecticide to rid the tree of the host beetles. In this manner, you may be able to localize the infected areas. Though the disease will still be able to spread throughout the tree, it will do so much more slowly without the help of the elm bark beetles.
The next course of action often involves treating the tree with potent fungicides. These substances are injected into holes at the base of the tree. The idea is that the tree's vascular system will then transport the fungicidal agents through the tree. There are six different chemicals currently being used to treat Dutch elm disease. If you believe an elm tree on your property has contracted Dutch elm disease, contact an arborist near you to determine whether fungicidal treatment is an appropriate option.
