Forest Health
The balsam woolly adelgid is a non-native adelgid that has been infesting Utah's subalpine fir and white fir forests for the last decade. While this pest has been in the United States for over 100 years, it has only recently been found in the Interior West. The devastating potential of the balsam woolly adelgid for Utah's true fir forests is unknown. Where it has infested mortality of up to 50% of trees has been noted and this has been found to increase fuel loadings - an important consideration for the drying subalpine forests in Utah. It appears to preferentially infest subalpine fir, where its presence is indicated by gouting, flagging, and the presence of 'woollies' on the bark (see pic), and sometimes mortality. It is known to infest and kill white fir, but the occurrence is much less common. We are studying the possible factors that control what stands this invasive adelgid is likely to attack, and what factors might control its spread within and among stands.