Oh my yes, it is killing trees," responded Beth Wilson, horticulture Extension agent for Pulaski County, when asked about presence of emerald ash borers. She pointed to ash trees planted on South Main Street near Pulaski County Public Library that " ... are about all gone and ash trees are dying all over the county."
There are 6 million ash trees in Pulaski County, fourth largest number of any county in Kentucky. A high infestation will cause a major impact on Pulaski County forests and lawns.
"You can treat trees up to 20 inches in circumference," Wilson said. "Insecticides are available ... mix in a 5-gallon bucket and pour around the base ... this must be done annually," she said.
For ash trees larger than 20 inches in circumference, an injection is necessary by tree professionals. Applying protective insecticide treatments to a healthy ash tree to prevent an emerald ash borer infestation is the best strategy for managing the insects. However, if a tree becomes infested and the infestation is detected early, you may be able to treat an ash tree to prevent further damage, and help the tree recover.
Due to expense of insecticide treatments for emerald ash borers, consider the value of a particular ash tree in relation to insecticide treatment costs before making any treatments. Proper use of insecticides can over time help maintain the health of high value ash trees. Lower value ash trees are not ideal candidates for emerald ash insecticide treatments, according to Wisconsin Horticulture Division of Extension.
Newly emerged adult emerald ash borers are most active when it is warm and sunny. They feed for several days before mating, chewing irregular notches along leaf margins. Mated females will feed for another week or two before laying eggs in bark crevices or under bark flaps on the trunk. One female will lay between 60 and 90 eggs, the UK agriculture college says.
The canopy of infested trees begins to thin above infested portions of the trunk and major branches because the borer destroys the water and nutrient conducting tissues under the bark. Heavily infested trees exhibit canopy die-back usually starting at the top of the tree. One-third to one-half of the branches may die in one year. Most of the canopy will be dead within 2 years of when symptoms are first observed.
Although difficult to see, the adult beetles leave a D-shaped exit hole in the bark, roughly 1/8 inch in diameter, when they emerge in June, according to Emerald Ash Borer Information Network.
Quarantine regulations for the emerald ash borer now include the entire state. This federal order directly affects the wood and nursery industries because it regulates the interstate movement of ash nursery stock, green lumber, waste, compost and chips of ash species and firewood of all hardwood species.