Exotic Invaders in Meigs County

Attention Meigs County!! We are being invaded by creepy, crawly creatures. No it’s not the recent trick-or-treaters, but a flying tree-killing insect known as the invasive emerald ash borer (EAB). As some of you may be aware, the emerald ash borer (EAB) is in Meigs County and killing ash trees at an alarming rate. With the help of cooperative landowners, I have been able to capture many EAB larvae within the county.

The EAB invasion is the most costly biological invasion by an exotic forest insect to date. An infestation of EAB is always fatal. They can kill a mature ash tree in as little as two to four years.

Ash trees are an important tree species in the natural forests of Ohio. There is an estimated 3.8 billion ash trees in Ohio which accounts for 12 percent of the total forest land. Along with being a popular shade tree, the ash’s wood is harvested for firewood and to make baseball bats, tool handles, and furniture.

The emerald ash borer was first detected in the United States in Michigan in 2002. The following year cases of it were confirmed in Ohio. The Ohio Department of Agriculture reported the first infestations of EAB in Meigs County this year (2014). To date, the EAB has spread as far west to Colorado, east to New Hampshire, south to Georgia and north to Canada. Since the EAB is so widely spread, there are no longer quarantine regulations in place for emerald ash borer within the state Ohio.

EAB completes its life cycle in one or two years. In southern Ohio, adult emergence generally begins in early May, peaks around mid-June to early July, and is complete by early August Adults can live 3–6 weeks and feed on the ash tree foliage. Females produce, on average, 40 to 70 eggs. They lay their eggs individually in the cracks and crevices of the bark and eggs hatch within approximately two weeks. The larvae chew though the bark and into the cambial region of the tree. They feed on the tree’s phloem and outer sapwood for several weeks, disrupting the tree’s ability to transport water and nutrients. Feeding is complete in autumn and the pre-pupal larvae overwinter in the outer sapwood or in thick bark.

Typically, the EAB colonizes the upper portions of the canopy of large trees before the main trunk, making it difficult to detect an early infestation. When a tree has been affected for at least one year, “D”-shape exit holes with a width of one-eighth inch will be left on the bark by the emerging adult. Another way to detect the EAB is by looking for serpentine or “S”-shape feeding galleries left by the feeding larvae etched into the underside of the bark and the outer sapwood. The galleries are usually filled with tightly packed excrement and sawdust. A tree with an EAB infestation will exhibit other symptoms and signs such as: canopy and top die back, thin vertical splits in the bark (2-5 inches), unnatural shoots sprouting from the base and/or trunk of the tree, and usually heavy woodpecker activity (especially in the winter).

If you want to save your ash tree, there are several insecticide options and methods available. Insecticide methods include: trunk-injection, noninvasive basal trunk sprays, soil applications, and protective cover sprays. For more information on EAB treatment or general information on EAB contact your local extension office or visit http://emeraldashborer.info.