WINTER PARK —In the aftermath of the bark beetle epidemic, Grand County’s lodgepole pines are seeing an uptick in attacks from another pest.
The pine needle scale is a small insect that latches onto needles and feeds on sap. The bugs cause pines to appear faded or yellow. Like the mountain pine beetle, the pine needle scales are native to area forests. Foresters always see some amount of pine needle scale in the area. Populations are usually kept in check by natural predators and cold weather.
“We’ve been seeing (popoulations) grow for the last three years, but this year we saw a huge influx,” said Ryan McNertney, assistant district forester for the Colorado State Forest Service Granby District. “They’re showing up on a landscape scale as opposed to neighborhoods or a person’s lot.”
According to McNertney, the insects are hitting all sizes of lodgepole, mostly around Fraser and areas east of the YMCA of the Rockies.
“I don’t have a good answer for why. We’ve been trying to figure that out, but we don’t know,” McNertney said. “It could be drought stress or any number of factors.”
There’s no cost-effective way of treating trees, but early on or with small attacks, McNertney said trees with an afflicted branch or two can be pruned. A press release issued by the Colorado State Forest Service noted pine needle scale usually does not cause tree mortality, and large outbreaks of the bugs are rare in the state. A deep winter freeze could help drop populations locally.
“That’s normally how it’s kept in check,” McNertney said.