Discovery of Forest Pest in Missouri Triggers State, Federal Response

The Emerald Ash Borer Could Be Devastating to Missouri Trees.


State and federal officials are working overtime to determine the extent of an emerald ash borer infestation at Lake Wappapello and develop a strategy for containing the problem.

The infestation came to light July 23 when U.S. Department of Agriculture (USDA) scientists discovered seven suspicious beetles on traps at the U.S. Army Corps of Engineers’ Greenville Recreation Area in Wayne County. Officials with the USDA confirmed the identity of the insects Friday.

Collin Wamsley, state entomologist with the Missouri Department of Agriculture, said his agency and the Missouri departments of Conservation and Natural Resources are prepared to deal with the infestation. Before proceeding, however, both state and federal agencies need to determine the its extent.

"Although it is a disappointment to find the early detection of the emerald ash borer, it is not a surprise," said Wamsley. "We have been preparing for an event like this for some time. Right now, we are doing what we can to determine the location of the emerald ash borer. We hope to have that information soon and begin the next steps in battling this pest."

Wamsley said the first steps that will be taken include conducting visual searches for emerald ash borers and placing more traps around the initial detection site. This is under way. The results of these surveys will dictate further actions.

The emerald ash borer is a small, metallic green beetle native to Asia. Its larvae burrow into the bark of ash trees, causing trees to starve and die. While the emerald ash borer does not pose any direct risk to public health, it does threaten Missouri’s ash tree populations.

Ash trees make up approximately 3 percent of forests and 14 percent of urban trees in Missouri. Since no ash trees in North America are known to be resistant to the pest, infestations are devastating to these tree species.

Missouri is the ninth state to have a confirmed emerald ash borer infestation. The pest was first found in Michigan in 2002. Since that time, seven other states (Ohio, Indiana, Illinois, Maryland, Pennsylvania, West Virginia and Virginia) have confirmed infestations. Missouri is the farthest south and west of any other known emerald ash borer infestation.

The emerald ash borer trapping effort that revealed the infestation is part of a monitoring program started in 2004. It is Missouri’s contribution to a nation-wide early detection effort coordinated by USDA in partnership with the Missouri departments of Agriculture, Conservation and Natural Resources and the University of Missouri.

Emerald ash borer traps are purple, prism-shaped devices with sticky outer surfaces. The borers are attracted by the color and by chemical scents that mimic a stressed ash tree. Insects that land on the traps are stuck and can be identified by periodic checking. So far, emerald ash borers have not shown up on any other traps throughout the state.

Although adult emerald ash borers are strong fliers, they are less likely to travel long distances when plenty of host trees are available nearby. However, they can move long distances on firewood and nursery stock. State officials urge Missourians not to transport firewood from one site to another. Instead, they suggest that campers buy firewood locally.

"The discovery of this highly destructive pest at a campground is a strong indication that it probably arrived in firewood," said Conservation Department Forest Entomologist Rob Lawrence. "If people knew how devastating this insect can be, they would never consider bringing firewood from out of state."