What is that purple thing in the tree? A trap for EAB; Please leave it be

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This purple box is a trap for the Emerald Ash Borer (EAB), an invasive insect from Asia that can kill our native ash trees. It has not yet been found in Maine. These purple traps will help look for EAB, hopefully before it becomes established. (Times photo by Cherri Crockett)

REGION- If you've been paying attention as you drive down the road throughout Oxford and Franklin counties, you may have noticed prism-shaped purple boxes hanging from the trees. These traps have been placed by the Maine Forest Service (MFS) to help monitor the presence of the Emerald Ash Borer (EAB).

This invasive insect is native to Asia and can decimate all species of ash throughout North America. It was first discovered in Michigan in 2002 and the MFS is working diligently to ensure they are notified of its presence as soon as it hits the western borders of the state.
According to the MFS, Maine began participating in a national purple trap survey program in 2007. The number of traps hung in Maine has increased as EAB has been detected closer to our borders. In 2011, 200 traps were deployed in Maine. In 2012, there are plans for 955 traps to be hung across the state with the majority in Oxford and Franklin counties.

The traps are made of corrugated plastic and fold into a prism shape. A scented lure, which is a combination of manuka oil and a leaf-blend compound, is hung inside the trap. The outside surface is covered with a sticky glue. The trap is hung in the canopy of ash trees. The color and scent of the trap attract flying adult beetles, which then get stuck in the glue.

The traps have been set by the MFS and other cooperators.

The groups expect adult flight period to begin in mid June. As the adult leaves the host tree a characteristic “D” shaped exit hole is created. Many of the little green beetles people turn in beginning in early May are tiger beetles. These are beneficial, preying on other insects including many pest species.
In July, the traps will be checked for EAB and lures replaced. EAB adult flights, mating and egg laying activity peaks during this time. Activity of the ground nesting wasp that preys on metallic wood boring beetles, including EAB is apparent by mid-July.
Traps will be removed and checked for EAB during August and September. Adult beetle flights will be largely over. Larvae hatched from eggs deposited on the bark of ash trees would be creating meandering tunnels beneath the bark as they feed on nutrient-rich bark and phloem (living tissue that carries organic nutrients).

The MFS believes that one of the best tools for invasive insect detection is public awareness. To learn more about Emerald Ash Borer, or if you think you've found it, please visit www.maineforestservice.gov/purpletraps.htm or call 287-2431. And, remember, please let the traps be.