Coconino National Forest Teaming With NAU To Help Control Pests That Are Killing Aspen Trees

Over the past two years, foresters and researchers have been trying to understand the effects of oystershell scale, or OSS, on aspen and softwood trees around the country. OSS is an invasive insect that sucks plant fluid out of a tree and eventually killing the host tree. They start as an egg, then growing into a “crawler” which are less than one millimeter long and disperse on a host to establish a feeding site. Mature OSS are then formed, which can grow to two-and-a-half millimeters, resembling a miniature oyster shell that sticks to the trees. Coconino National Forest has been teaming up with the Northern Arizona University’s School of Forestry to understand the threat and help with damage control. Researchers believe the OSS effect is due to climate change and the unique characteristics of the species. Invasive and forest-damaging pests have caused a large decline in many tree species worldwide. The Forest Service and their partners are working to better understand and control these pests. For more information, go to fs.usda.gov.