Ash - Lilac Borer
Hosts: Most common are Green and White Ash and Lilac.
Damage:The larvae borer holes into the trunk and main crotch area causing swelling and cracking of the bark. Dieback or death of the host can occur if attacks are numerous enough.
Control: Plants should be maintained in good health and vigor to discourage infestation. Systemic insecticides are available to control infestations.