The emerald ash borer is a pest that kills ash trees.
The iridescent, metallic-green beetle is about one-third to one-half-inch long. Its larvae live under ash tree bark, making S-shaped tunnels that cut off the flow of water and nutrients in the tree. Adults eat ash leaves.
Adult emerald ash borers can fly about a half-mile to lay hundreds of eggs in tree bark. The insect is transported over larger distances by people moving firewood or infested nursery stock.
• The borer is an invasive species, native to Asia, that was first discovered in the U.S. in 2002 in Michigan. It probably arrived in shipping materials and has spread in the Midwest and Eastern forests.
• Because larvae are hard to detect living under the bark of trees and adults are difficult to trap until there are large numbers, researchers determined it probably arrived a decade before.
• The beetles attack only ash trees, so foresters suggest choosing other varieties for landscaping.
• The only known control is preventive treatment with various chemicals every one or two years. Once a tree is infested, it will weaken and die.
For more information, go to www.emeraldashborer.info or www.mdc.
Sources: Missouri Department of Conservation and Michigan State University