Apple bark borer
Synanthedon pyri
Eggs are very difficult to see and are laid singly on the trunk of the tree. Larvae of all three species are dirty white with a reddish-brown head and thoracic shield (area behind the head). Pupae are small, yellow-brown and sometimes observed as pupal cases partially protruding from the adult exit holes in the trunk or infested burr knots. Adult clearwing moths possess transparent wings with striking dark markings along the margins. They are daytime flyers and are often confused with wasps. There are numerous species of clearwing borer males which are attracted to and can be caught in commercial pheromone traps. Fortunately, they are relatively easy to distinguish from one another with little training.
Apple bark borer are very similar to dogwood borer, but have a wedge-shaped anal tuft and distinct orange mark on the wings.