27 
The Lilac Borer 
(Podosesia syringcc Harris) 
Among the borers whose instincts lead the female to choose, 
for the deposit of her eggs, scars or injured places on the bark of 
trees and shrubs, with the effect greatly to increase the injury and 
Fig. 25. Trunk of ash in one of the parks in Chicago, showing injury 
by ihe l-ilac Borer, J'ouosesui syrihga. 
to prevent its healing, is a species commonly known as the lilac 
borer {Podoscsia syringcc), because it was first noticed to infest 
lilacs. It is much more important, however, by reason of its in- 
juries to various species of true ashes,* and to the mountain ash, 
*It has been found injurious to the lilac (Syringa sp.), to the mountain 
ash (Sorbus americatia), and to the white, green, and English ashes {Frax- 
inus avicricana, lanceolata, and excelsior). 
