Hosts

• The lilac borer does infect other plants. The University of Kentucky notes that lilac, ash, privet, flowering dogwood and Sargent crab apple can be harmed by this pest. According to North Carolina State University, shrubs in the olive family (like Osmanthus) and mountain ash can also be damaged.
  
  

Control

• Treat plants and shrubs one week after they bloom with an insecticide labeled for borer control. The timing is crucial, since the insecticide needs to be on the bush in the time between the borer eggs hatching and the insects entering the tree.
  
  

Damage

• Lilac borers can kill the host shrub or tree if not controlled. These borers damage the bark, creating wounds and holes.
  
  

Other Borers

• Just as the lilac borer infects trees other than the lilac, other kinds of borers can harm your lilac tree, including the flathead appletree borer.