Trees falling victim to disease
Disease and insects are killing trees in Washington and Greene counties.
Some of the issues plaguing trees have been exacerbated by the recent weather. This can be seen quite prevalently in Colorado blue spruce trees.
According to retired forester and Waynesburg resident Bill Wentzel, blue spruces are falling victim to Rhizosphaera needlecast, which is a fungal disease. The disease causes the needles of the trees to turn purple, then brown and eventually they will begin to fall from the tree. The heavy rainfall the region has seen recently provides the disease with the conditions it needs to continue to spread.
The rain does not mean all doom and gloom for trees, however, as there are cases where it is actually helpful.
Take the yellow poplar weevil, for example. This insect infects tulip poplar trees and will turn their leaves brown. The pest raises alarms for some as it may appear to be a tick, but they are not ticks and pose no threat to humans.
“We’ve had a bad outbreak this year,” said Russell Gibbs, Washington County service forester with the state Department of Conservation and Natural Resources.
Luckily for the trees, the weevil is native to this area and as such, has natural predators to help keep it in check. Both Wentzel and Gibbs are in agreement that the excessive moisture is beneficial to the poplars.
“The rain will help the trees overcome the stress,” Wentzel said.
A far more dangerous insect for trees is the emerald ash borer. This beetle larvae gets under the bark of ash trees and will kill not only the branches, but sometimes the whole tree. Unlike the yellow poplar weevil, the emerald ash borer is not native to this region. This means there are no natural controls that can help contain the beetle. There are insecticides that can be used, but this is an expensive option that could also prove ineffective.
“Treatment may take up to six months to be effective, and may be temporary,” Gibbs said.
According to Wentzel, stingless wasps have been introduced to the environment since 2007 in hopes that a natural control for the beetle develops.
Gibbs pointed to another insect similar to the borer in that the area also has no natural enemy, the hemlock woolly adelgid. The adelgid, an aphid-like insect, is a “hemlock killer,” according to Gibbs, and attacks the trees by sucking the sap out of the base of their needles.
Gibbs said colder weather in recent years helped to keep them in check, but they are currently posing a problem. Like the borer, the treatment options for the adelgid are costly.