Conservation Officials Urge Memorial Day Vacationers Not to Move Firewood

By Jim Low, Missouri Dept. of Conservation

05-18-2009

The Missouri Department of Conservation reminds those who plan to camp over the Memorial Day weekend not to move firewood. Obtaining firewood at your destination is the most helpful thing anyone can do to keep Show-Me State forests safe from the emerald ash borer.

The borer – an attractive metallic green beetle – has killed millions of ash trees in several other states. The first infestation in Missouri was discovered last year at a campground in Wayne County.

“Firewood isn’t just the main way this pest spreads,” said Forestry Programs Supervisor Justine Gartner, “it’s practically the only way it spreads. If people are careful not to take firewood from place to place we can delay the spread of emerald ash borer.”

The emerald ash borer is an Asian beetle first discovered in North America in Michigan in 1992. The most likely source of that infestation was imported wooden packing materials. Since then the emerald ash borer is estimated to have killed more than 50 million ash trees in rural forests and city landscape plantings from Maryland to Missouri and into Canada. No North American ash tree species has been found resistant to the pest.

Most trees die three to five years after being attacked. The cause of death is damage to tissue beneath trees’ bark. This tissue carries water and nutrients between tree leaves and roots.

Without outside help, emerald ash borer infestations spread very slowly – one-half to two miles per year. However, the borers spend much of their lives tunneling beneath bark, and this has been the key to the pest’s rapid spread.

Moving one piece of firewood from an infested area can result in an outbreak in a completely new area hundreds of miles away. Infestations are hard to detect until they are well-established. Meanwhile, newly infested areas can be the source of other outbreaks if campers or firewood suppliers transport wood to other areas.

State and federal officials are working to determine the extent of Missouri’s emerald ash borer problem in order to combat it most effectively. One survey involves purple, triangular plastic traps. The traps measure approximately 1 foot by 2.5 feet. The traps are highly visible to people, but more important the color attracts adult emerald ash borers.

To make the traps even more effective, they are baited with an artificial attractant that mimics chemicals produced by stressed ash trees. Emerald ash borers sense these chemicals, which betray stressed trees that are particularly susceptible to parasites. Insects that land on the traps are caught in sticky material.

Approximately 1,000 of the traps are being placed within an 8-mile radius of the Corps of Engineers’ Greenville Recreation Area, where Missouri’s first infestation was discovered. Several hundred traps also are being placed at high-risk sites, such as campgrounds, sawmills and tree nurseries. When the traps are retrieved and examined in July and August they will reveal how far Missouri’s first known emerald ash borer infestation has spread.

The implications of the infestation are severe. Even before the emerald ash borer reached Missouri, ash trees here were suffering from “ash yellows” disease and a complex of insect and disease problems called “ash decline.” Forestry officials say these problems combined could produce devastation unlike any seen since chestnut blight all but exterminated the American chestnut from forests in eastern North America. For more information, visit mdc.mo.gov/firewood, mdc.mo.gov/forest/health/ashborer/, eab.missouri.edu or emeraldashborer.info/.

Large, triangular, purple traps are part of Missouri’s efforts to track the spread of emerald ash borers, a destructive forest pest. (Missouri Department of Conservation photo)