Studies have shown that once healthy hemlocks become infested by HWA, nutrients are depleted from the tree, leading to both tree decline and a reduction of the adelgid population. Since HWA is dependent on hemlock for nutrients, feeding on trees in poor health may affect the ability of the insect to obtain necessary nutrients and may consequently affect their physiological and population health.  Anne Jones and colleagues provide the first examination of HWA physiological and population health in relation to hemlocks of different health levels.

Read more: http://onlinelibrary.wiley.com/doi/10.1111/1744-7917.12240/abstract