EAB takes a toll in Caledonia

Craig Moorhead/The Caledonia Argus  Randy Bearbower with a freshly-felled ash tree in a Caledonia residential neighborhood.
Craig Moorhead/The Caledonia Argus
Randy Bearbower with a freshly-felled ash tree in a Caledonia residential neighborhood.

Craig Moorhead

The Caledonia Argus

The stately boulevard tree lay near its stump, over 16 inches in diameter.

“There’s going to be quite a few more of these…” Randy Bearbower said as he prepared to chunk up and haul off the ash tree. There were probably around 800 of the popular shade trees within the Caledonia city limits before the emerald ash borer (EAB) showed up, he noted.

Working as a private contractor, Bearbower has been assisting city crews and other private tree trimming professionals as infected ash trees are removed from boulevards. The work has been progressing steadily, with the removal of marked sets of 10 or 12 trees having been bid out to contractors whose stock and trade is safely dropping and cleaning up wood and brush. Bearbower said that between city employees and private workers, over 80 ash trees have already been taken down within the city since the first EAD appeard in the area.

“We budgeted $9000 for the removal of ash trees in 2016, and an identical amount in 2017,” Caledonia city administrator Adam Swann reported.

So cutting, cleanup, and the grinding of stumps continues.

Craig Moorhead/The Caledonia Argus  Woodpeckers have marked up this local EAB infested ash tree.
Craig Moorhead/The Caledonia Argus
Woodpeckers have marked up this local EAB infested ash tree.

Ash trees infected with EAB larvae are often easy to spot, since woodpeckers feed on the insects, removing the outer bark in their quest for a meal. The larvae tunnel beneath the surface of the trees. As they develop, then emerge as adults, the insects leave D-shaped exit holes in the outer bark. Those can be hard to spot, however, especially if they occur high in the canopy.

According to the Minnesota Department of Natural Resources, nearly a billion ash trees across the state are threatened by the invasive pest. EAB was discovered in the metro area in 2009, and showed up in the southeastern part of the state the following year. Houston County lies within the EAB quarantine area.   

It is against the law to remove ash logs and lumber, ash waste such as wood chip and mulch, and all hardwood firewood from quarantined counties.

Several insecticides are marketed to control EAB, but the expense of yearly treatments to keep the bugs from killing residential ash trees may discourage many homeowners from trying to save their shade trees.

Ironically, many ash trees were planted throughout the region to replace elms hit by disease decades ago. According to experts, EAB is thought to have arrived in the United States in wooden packing crates originating in China.