The ‘Common’ Lilac Borer was attacking Ash trees long before EAB showed up.
The Bronze Birch Borer attacks the beautiful and valuable White Birch.
The Zimmerman Pine Moth Borer has also been a long term problem, killing Scotch and Austrian Pines.
The Locust Borer attacks Locust and the Lilac Borer attacks Lilacs.
Although there are other Borers, these are among the most common.
Borers come from adult beetles that lay eggs in the cracks and crevices of bark. The larvae that hatch burrow into the bark and live just beneath it.
Their feeding and tunneling stops the flow of water and nutrients through the tree by cutting off the flow of conducting vessels. Leaves on branches above the damaged areas start yellowing and thinning. The top of the tree usually shows the earliest damage, and progresses downward from there.
An experienced Arborist can usually spot the telltale external evidence, which is different on all varieties of trees these insects invade.