Overview
The ash borer (Podosesia syringae), or lilac borer, is a clearwing moth in the family Sesiidae. It is found throughout North America and can be a pest of ash and lilac.
Appearance
Like other clear wing moths, ash borers have partially transparent wings due to a lack of colored scales on the wings. The body is brown with yellowing striping on the legs and abdomen, and can give the appearance that the ash borer is a paper wasp.
Hosts and life cycle
Ash borer adults feed on nectar and will lay their eggs in the bark of lilac, ash, and privet, but can attack closely related plants in its range within North America. Larvae feed beneath the bark by chewing into the sapwood. Larval feeding can destroy the tree's phloem, weakening and possibly killing already stressed or very young trees by increasing the potential for wind damage or wilting. Pupae overwinter in the feeding gallery and emerge as adults the following spring. Adults begin to emerge between April and July or 300 to 500 growing degree days above or about one week after full bloom of lilac.
Monitoring and treatment
From Wikipedia (CC BY-SA 4.0).