The invasive emerald ash borer was first detected in North America near Detroit, Michigan in 2002 and is speculated to have made its way across the ocean by hiding in wooden shipping crates. Its ability to disperse via human-facilitated mechanisms as well as biological means, coupled with the lack of natural predators and environmental suppressants has resulted in an alarming rate of infestation and a widespread ash mortality at a rate of 99%. The beetles lay their eggs within the deeply grooved crevices of ash trees for protection from predators. Once the eggs hatch, the larvae borer into the tree where they reside within the cambium, or the growing layer of the tree, for about 300 days while they develop. Here they eat through the phloem of the tree creating widely webbed and curved galleries which disrupt the flow of nutrients, water, and communicative chemicals from the roots to the branches of the tree, as seen in the image. The adults of the emerald ash borer chew through the wood and emerge from trees from a small and distinctive D-shaped exit hole, which is the final blow to the tree’s life, and it falls shortly afterwards.
Field work, permanent plot, Hueston Woods