Statewide effort intended to detect presence of invasive tree pest

Thousands of traps will be hung across Minnesota this week in a hunt for the emerald ash borer, according to the Minnesota Department of Agriculture.

State workers are expected to place in Koochiching County 120 of the approximate 6,500 purple detection traps to be placed statewide.

This is about 2,000 more traps than were hung in 2011. The trap is a three-paneled purple prism placed in an ash tree. A lure inside the trap smells like a stressed ash tree to the beetle. Once EAB, or emerald ash borer, is drawn to the purple detection trap, a sticky layer on the outside of the trap holds the beetle until MDA’s trappers can return and check for the insect.

Traps will be placed in areas identified by a risk-based model developed by the United States Department of Agriculture. If required, EAB traps may be placed on private property. Citizens are asked not to disturb traps.

“This trapping survey is one of the few options we have for detecting EAB,” said Geir Friisoe, MDA’s Plant Protection Division director. “That’s why it is so important that the public leaves the traps as they are so we can collect accurate and useful results.”

The trapping program has proven effective in the past. In August 2011, EAB was found in Winona County because of a positive find in a trap. Results of the survey will help MDA staff determine if any further action is needed to slow the spread of EAB.

Traps will not be placed in the four counties currently under quarantine for EAB: Houston, Winona, Hennepin and Ramsey.

The main purpose of the survey is to detect new areas of infestation that should be quarantined to prevent spread from the area. When an area becomes quarantined, it is illegal to move all hardwood firewood and ash wood out of the quarantine boundaries.

Questions about the traps and the trapping program can be directed to arrest.the.pest@state.mn.us or 888-545-6684. For more details about emerald ash borer, visit the MDA website at www.mda.state.mn.us/eab.

EAB is an insect that attacks and kills ash trees. The adults are small, iridescent green beetles that live outside of trees during the summer months. The larvae are grub or worm-like and live underneath the bark of ash trees. Trees are killed by the tunneling of the larvae under the tree’s bark.

EAB is native to eastern Asia but was discovered in Detroit, Mich., and Windsor, Ontario, in 2002. Indications are it may have been introduced to this area as early 1990. EAB has been spread in ash firewood, nursery stock and possibly other ash materials to a number of new areas.

Meanwhile, residents are encouraged to watch for signs of EAB on their ash trees. Potential signs of EAB include woodpecker damage, especially at the top of the tree; bark cracks or splits; s-shaped galleries under the bark; and, die-back of leaves in the upper one-third of the tree branches.