Lilac Borer, Ash Borer

Information from several sources describes the Lilac Borer--also known as the Ash Borer--as a clearwing moth in the Sesiidae family, found throughout the U.S. east of the Rockies.

The Lilac Borer strongly resembles the aggressive paper wasp (Polistes fuscatus): black and yellow bands, prominent antennae and hind legs, but growing larger, to a length of 3/4 to 1-1/2 inches, and lacking a stinger.

Favored species for the Lilac Borer/Ash Borer include European Ash, Lilac, Privet, and Mountain Ash. The larvae of this insect destroy target trees and shrubs by burrowing into the wood beneath the bark, which swells and splits; over the winter, the larvae move into the heartwood.

Controls for this serious pest include spray application 10 to 14 days aft... read moreer emergence--as early as April 22 in Colorado--or pheromone traps set out from mid-May to early June, depending on region. Contact your extension office for exact emergence dates in your zone.

Photos of Lilac Borer damage courtesy Toni Leland
An excellent photograph of an adult (clearwing moth) can be found at http://www.coopext.colostate.edu/TRA/PLANTS/index.html#http:...