An old pest is causing new problems in the Ohio River Valley. The tulip scale insect has always preyed on tulip poplar trees, but the past two years of mild winters mean there’s a much higher population than usual.
The tulip scale insect attaches to twigs on tulip poplar trees, sucks sap out of the bark and releases a clear, sticky sugary substance that’s commonly called “honeydew.” The honeydew is annoying—it falls onto lawns and cars—but the real danger is to the trees.
Phil Marshall is the director of the Indiana Department of Natural Resource’s Division of Entomology and Plant Pathology. He says the scale insects are native to the region, and they’ve co-existed with tulip poplars in the past. But the past two years of mild winters mean the insects are out of control.
“Those cold temperatures can help to kill off the population and bring it back down to the normal background level where we always have a few around, they just don’t do that much damage to the tree at all,” he said.
Marshall says the trees are also sensitive to drought, and a combination of scale insects and dry weather could be fatal for tulip poplars.
“If we don’t have moisture, [homeowners are] going to have to keep the tree watered,” he said. “If not, that could lead to the death of the tree, maybe later this year or possibly in 2013 or 2014.”
Some pesticides are effective against the scale insects, but Marshall says those are best when used early in the spring.