Lilac Borer

Lilac Borer or Ash Borer is considered a clear wing moth but adult females can resemble the appearance of wasps. The host plants for the Lilac Borer include: Lilac (Syringa spp.), Ash (Fraxinus spp.), Mountain Ash (Sorbus) and privet (Ligustrum spp.). Borer larvae cause damage by feeding on the phloem and outer sapwood, leaving behind tunnels that can be over 7 cm long and 1 cm wide. Most trees can heal from the wounds created from the Ash Borer. But damage can occur if the main trunk becomes swollen and the bark cracks and separates from the inner wood. Trees that are stressed are more susceptible to the Ash Borer.

Scientific Name: Podosesia syringae

Common Name: Lilac Borer (Ash Borer)

Type: Pest

Family: Sesiidae

Control Methods

The most critical control method is keeping trees that are susceptible stress-free. Once Ash Borer is established it is difficult to eradicate. Pruning out older limbs that are closer to the base can help to prevent establishment. Pruning should be avoided when adult moths are in flight. Certain sprays can be used to limit or eradicate the Ash Borer. Spraying should be done when the Ash Borer is in its adult stage (Moth) when it has started flying. Timing is important because when the Ash Borer is in the larval stage it is protected inside the tree.