They peel all of the bark to look for larvae
CALUMET -- Chainsaws in hand, the Slow Ash Mortality (SLAM) team, led by Michigan Tech professor Andrew Storer, is returning to the woods to cut and peel the girdle trap trees they set last spring.
"By girdling the trees [to weaken the bark], they became very attractive to the beetles, but we're also finding older stage larvae, which means this tree was infested before we girdled it," says Storer. "It tells us the beetle is more widespread than we originally thought."
Peeling and processing all of the pieces can be tedious, but it's important to be thorough.
They're removing one layer at a time, carefully picking out each larva they find beneath the bark and recording its size.
"You have to be very detailed, so we're removing very small pieces of bark," says field technician Cindy Ricker. "We have found galleries on top of other galleries or at depths greater than we would have expected, so we're trying to do our best."
They've started with the traps closest to the Calumet area which they expect to be fully infested. It'll take them approximately two months to process close to 500 girdle trap trees.
"We'll look at the level of infestation throughout the area and if, outside of what we consider to be the center, trees are popping up with larger infestations, we'll know it wasn't a naturally occurring spread," says forester Brian Feldt.
Between the girdle traps and the prism traps removed earlier this fall, the slam team can create a better map of the current infestation and density which will help in the next year as they work to prevent the population from spreading.