This week’s invasive species is the emerald ash borer (Argrilus planipennis). This small insect was first found in Ontario in 2002 and has been wreaking havoc on the province’s Ash trees ever since.
Native to: Asia
Look alikes: Six-spotted tiger beetle
Identifying Features: As its name suggests, the emerald ash borer is a metallic green beetle that attacks Ash trees. It is 8.5-14mm long. When emerald ash borers exit a tree, they leave behind a capital D-shaped mark on the tree.
Why it’s problematic: There are no known natural predators of the emerald ash borer. The species is extremely threatening for Ash trees, because once it has invaded, the mortality rate for the tree is almost 100%. This results in a loss of food source and habitat for many other species. They will attack both healthy and stressed Ash trees.