COLUMBIA, Missouri – Foresters with the Missouri Department of Conservation (MDC) have confirmed the presence of an invasive tree pest in two new counties in central Missouri. The Emerald Ash Borer (EAB), an exotic beetle that kills ash trees, has spread to Camden and Miller counties. The destructive insect has now been confirmed in 33 Missouri counties, and the City of St. Louis.

EAB is a species of small, metallic green beetles native to the Asian continent. It attacks all species of ash trees, and kills nearly all trees it attacks. At approximately a half-inch long, the green adult feeds on leaves and does very little damage to trees. However, in its larval stage, the insect kills trees by feeding on the water- and nutrient-conducting tissues just under the bark.

“In many cities, ash trees account for 20-40% of the urban forest, which is bad news for homeowners and taxpayers,” said MDC Forest Entomologist Robbie Doerhoff. “EAB is estimated to cost Missourians more than $180-million in tree treatments, removals, and replacements over the next 20 years.”

EAB first appeared in the United States in Michigan in 2002 – most likely imported in packing crates and pallets made of EAB-infested wood. The pest first appeared in Missouri in 2008 at a campground near Lake Wappapello in the southeast part of the state.

EAB populations naturally spread only a few miles each year. However, humans can move EAB hundreds of miles in a single day. The adult beetles can emerge from ash firewood or logs for up to two years after harvest.

“Moving firewood can give these pests a free ride to new locations where they can start infestations that destroy trees, decrease property values, and cost lots of money to manage,” said Doerhoff. “We encourage people to find firewood as close to their campsites or bonfires as possible to reduce this threat.”

A federal quarantine currently restricts the movement of all hardwood firewood and ash wood products from Missouri into areas not known to have EAB.

“All communities in Missouri need to take a look at how many ash trees they have and start making plans for how they will deal with these trees when EAB arrives,” said Doerhoff. “If you have a healthy, high-value ash tree in your yard, it can be treated with insecticides that will protect it from EAB. However, these treatments can be expensive and must be applied every year or two to guarantee protection. For some ash trees, the best option is removal and replanting with a different species such as an oak native to Missouri.”

MDC encourages Missourians to learn to identify signs of EAB and report possible infestations in counties where the pest has not yet been confirmed.

For a map of EAB’s spread across Missouri, detailed information on identification, and a guide on insecticide treatments, visit eab.missouri.edu. Report suspected EAB damage in new counties to a local MDC forester, call MDC’s Forest Pest Hotline at 866-716-9974, or email forest.health@mdc.mo.gov(link sends e-mail).

tree images

These tunnels, or S-shaped galleries under the bark of an ash tree reveal signs of an EAB infestation. Learn more about how to identify this invasive pest at eab.missouri.edu.

EAB being compared to a penny