Emerald Ash Borer confirmed in new Missouri locations
With emerald ash borers confirmed in Missouri, Department of Conservation foresters say homeowners need to make plans now to protect or replace their ash trees.
At the start of 2015, the borers had been identified in 11 Missouri counties, including the Kansas City region, the southeastern part of the state, and St. Charles County.
However, the Missouri Department of Agriculture recently confirmed the insects have been found in the St. Joseph area (Buchanan County), both the City of St. Louis and St. Louis County, southeastern Missouri (Oregon County), and Hannibal (Marion County) in northeast Missouri, which represents the first detection in the northeastern part of the state. Missouri now has 15 counties and with known beetle populations. It’s likely in other counties, but has not yet been reported.
An emerald ash borer is an Asian beetle that tunnels under the bark of an ash tree, disrupting the flow of water and nutrients and eventually killing the tree. Even fully developed, the dark-green, metallic beetle is only about a half-inch long. Larvae leave S-shaped tunnels under bark and adults emerge from D-shaped exit holes. As their numbers grow, more damage occurs.
If homeowners live within 15 miles of where the borers have been detected, they will need to decide if they want to save a valued ash tree by beginning treatments next spring or if they want to plant another species as an eventual replacement. In time, all untreated ash trees in areas harboring the beetles are expected to succumb.
Ash trees can be protected. Treatment costs vary by the size of tree and type of treatment used. The cost can be as little as about $25 annually for a do-it-yourself treatment on a small ash tree, and as much as a few hundred dollars to hire a professional arborist to prevent infestation in a larger ash tree, which cannot be effectively treated on a do-it-yourself basis.
Because insecticides are most effective from early May to June when adults are active and larvae are beginning to develop, it’s too late to respond this year. However, some treatments may need to be applied earlier in the spring to be most effective when adults emerge later.
Most of the emerald ash borer movement is due to the transportation of firewood. To help slow the spread of the pest, Department foresters recommend that firewood not be moved from one area to another. People burning wood, including campers, are urged to buy locally harvested wood.
All Missouri counties are now under a federal and state quarantine preventing the movement of ash nursery stock, any parts of ash trees, and hardwood firewood out of the state of Missouri.