THE POPLAR AND WILLOW BORER 



465 



Although the beetles do not fly, yet they are undoubtedly well able to 

 walk considerable distances. How far has not been determined, but they 

 have been found a goodly distance from any of their food plants resting 

 quietly on the trunks of various trees. This is especially true in the spring. 



FlG. 113. A PILE OF DISCARDED CAROLINA POPLARS IN A NURSERY 



Mating does not occur until ten days or more after emergence. This 

 period is spent largely in feeding, and the beetles do considerable damage 

 at this time to the vigorous growing shoots. Copulation occurs freely 

 and a pair may remain several days in copula. Not only does mating 

 last a considerable time, but it may be repeated again and again at 

 different times. 



Egg laying 



Shortly after copulation the females seek out suitable places for the 

 deposition of their eggs. They choose branches or parts of the trees 

 more than a year old, and deposit their eggs in the corky parts of the 

 bark. The eggs have never been found 

 in one-year-old stock, but only in 

 wood two years old or older. Favorite 

 places for egg laying are lenticels (figs. 

 114 and 115), scars, bases of branches, 

 injured areas, or about the base of 

 buds where the bark is somewhat 

 thick. With her beak closely applied 

 to such an area the female beetle at 

 once begins to eat into the bark. 

 Gradually she deepens the round hole 

 until her entire beak is buried, up to the eyes. The time required for 

 this operation varies from a few minutes to thirty or forty minutes. At 

 the bottom of the hole the beetle may round out two or three small 

 lateral cavities, or she may be content with only one. In the majority of 



FlG. 114. EGG PUNCTURES AT THE 

 SIDES OF LENTICELS 



