The emerald ash borer (EAB) is threatening more than 7.5 billion ash trees in the United States and Canada. Emerald Ash Borer Prevention is therefore very much on the mind of everybody who has ash trees growing on their property. To understand how this particular insect infestation can be prevented, it is necessary to understand the Emerald Ash Borer beetle itself.
The EAB is an invasive beetle species that originates from Asia. It made its first appearance in North America around the end of the 20th century and is spreading fast. The insect starts emerging from whatever ash tree it overwintered in, when the accumulated degree days in a particular area reaches 450-500. The newly emerged beetles feed on only ash leaves for about a week until they are mature enough to mate. Then when old enough to seek a mate they virtually stop feeding and focus on mating and laying eggs for the rest of their 2-3 week life. The female lays its eggs in the crevasses of the bark. When the eggs hatch 7-10 days later, the larvae burrow through the bark to the soft tissue (phloem) underneath which the tree uses to transport sugar throughout the tree. As they devour this carbohydrate rich tissue, the tree loses it ability to store the current year’s sugar being produced by the leaves through daily photosynthesis. Then the following year the tree may be unable to draw from it’s normal sugar reserves when it attempts to “leaf out” in the spring. It can take several years from the initial infestation to any visible damage showing, making it difficult to diagnose and prevent.
Emerald Ash Borer Prevention is necessary for all ash trees that are situated in or close to affected areas. So the first step in determining the level of danger is to know if an infestation has been reported nearby. The generally accepted “Danger Zone” is within a 15 mile radius or less. If that is the case a preventive treatment is strongly recommended.
This kind of treatment consists typically of two phases, soil and trunk treatment. In the first phase, in April, the soil around the trees is treated with an insecticide, fertilizer and a root stimulant. In May or June follows the second phase that consists of injecting an insecticide directly under the bark of the ash trees. If this prevention schedule is repeated for at least 4 to 5 years, chances are good that minor infestations are stopped in the onset and loss of trees can be avoided completely.
