How the Emerald Ash Borer Beetle Affects the Ash Tree

The adult emerald ash borer beetle has been destroying the ash trees of North America since the early 1990s when it first arrived on our shores, probable in a cargo ship from an Asian country. The adults do little harm as they feed on the leaves of the ash tree, but when it comes time for the female to lay her eggs, the tree is destined to die.

The female deposits her eggs in the crevices of the bark in early spring, when an ash tree is most vulnerable. Spring is when a tree’s sap starts to rise and this starts new cambium growth, which loosens the bark and allows the larvae to tunnel into the cambium layer.

This cambium layer is a thin, but living and vital part of any tree’s health and growth. Severely wounding or destroying it results in the death of the tree. Cambium is responsible for healing wounds to the tree, new bark and wood growth and transporting water and life giving nutrients in the tree.

When the eggs hatch, the larvae tunnel under the bark where they feed on the cambium layer between the tree’s wood and the bark, resulting in S-shaped tunnels that eventually spread around the tree and throughout the branches.

State and federal agencies have made this problem a priority and scientist in the US, Japan, China, Mongolia, Korea, the Russian Far East and Taiwan are working at a feverish rate to learn more about the beetles. They hope to find a cure for already infested trees as well as a predator to stop the beetles. If not successful, the ash tree will become extinct on the North American continent.

When these scientists learned that, the beetles flocked more quickly to a wounded ash tree they set about discovering why, and found that a stressed ash tree produces four compounds that are picked up by the antenna of the emerald ash borer beetle, luring it to the tree.

Using this information, they designed a baited trap for the beetles, which is used in areas around infected ash trees to help study the spread of this highly destructive insect. They are also looking into the possibility of releasing a sting-less Asian wasp that lays her eggs on the larvae of the emerald ash borer beetle, which serves as food for the tiny wasps.

The affects of the emerald ash borer beetle on ash trees has resulted in the death of countless trees, which has resulted in the loss of billions of dollars. Aside from the monetary loss, there are at least 20 known species of butterflies and moths that depend on the ash tree for survival.

We can’t even begin to know what all the consequences will be if all the ash trees are destroyed by the emerald ash borer beetle. The world’s eco-system is a balancing act and when you remove one single thing from the equation, everything else will shift too.