Emerald ash borer (EAB)
Emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an exotic beetle that was discovered in southeastern Michigan near Detroit in the summer of 2002. The adult beetles nibble on ash foliage but cause little damage. The larvae (the immature stage) feed on the inner bark of ash trees, disrupting the tree’s ability to transport water and nutrients. Emerald ash borer probably arrived in the United States on solid wood packing material carried in cargo ships or airplanes originating in its native Asia. As of October 2018, it is now found in 35 states, and the Canadian provinces of Ontario, Quebec, New Brunswick, Nova Scotia and Manitoba.
Most of the emerald ash borer life cycle takes place below the bark. Woodpeckers readily probe for larvae feeding beneath the bark, and often reveal infested trees during the winter months. These trees become covered in light-colored “flecking” as woodpeckers remove the outer bark.
As tunnels (called galleries) from feeding larvae accumulate and disrupt the flow of a tree’s nutrients, trees begin to show signs and symptoms of the infestation. Once symptoms have started to show, trees generally die within one to three years.
Emerging adult beetles chew characteristic 1/8-inch-wide, D-shaped exit holes that can be useful in confirming infested ash trees. Because the holes are small and frequently high in the tree, they can be difficult to find.
Individual trees can be protected from emerald ash borer using certain insecticides. These insecticides can be used preventively, applied when the insect is first detected near the neighborhood. Most of the emerald ash borer insecticides can also be used effectively a couple of years after emerald ash borer has first colonized a tree, when populations of the insect are still low and tree damage is minimal. One of the insecticides, emamectin benzoate, has been demonstrated to often allow tree recovery as a “rescue treatment” even when emerald ash borer injuries have begun to produce as much as a 30 percent reduction visible thinning of the leaf canopy of the ash tree.
Healthy or lightly infested ash trees can be treated using systemic injectable insecticide to prevent infestation. This can be done using mauget tree injection capsules to inject pesticides such as Mauget Imicide and Mauget Dinocide. Another option is to use Arborjet’s tree IV or Quik Jet system to inject products like Tree-age g4 or tree mec inject, or injectable imidacloprid products like Ima-jet 5%