05/11/2026
Take good care of your lilacs and keep an eye out for the Lilac Borer!
“Keeping ash and lilac healthy, such as by providing supplemental water during drought, can help limit infestations. Removing old, damaged lilac canes also helps.”
This is the Lilac borer (aka Lilac-ash borer) Podosesia syringae. This may look like a wasp, but it is not! The adult lilac borer is actually a moth and does not sting. Adults are flying and laying eggs now (May) in Nebraska. Lilac borer was our most serious insect pest of ash before emerald ash borer appeared, especially on young, stressed trees. Larvae tunnel into the trunk and branches of ash, but they also attack lilac, especially at the base of the canes.
Keeping ash and lilac healthy, such as by providing supplemental water during drought, can help limit infestations. Removing old, damaged lilac canes also helps.