PROTECTION 157 



forming a tunnel but little larger than the diameter 

 of the beetle, which is known as the egg gallery, 

 These egg galleries vary in shape from straight to 

 winding, and in length from ten to forty inches. 

 As a rule, male and female beetles work together in 

 one gallery, and the eggs are deposited along the 

 sides of the gallery, often in little pockets. When 

 the tunneling and egg-laying process of the adult 

 beetles is completed, their activity ceases, and they 

 are usually found dead at the upper end of their 

 galleries. The larvae hatch and begin their work 

 by burrowing across the cambium at right angles to 

 the egg galleries. The complete girdling of the 

 cambium layer is not accomplished until the larvae 

 have completed their work, and the numerous larval 

 galleries, by joining one another, form a complete 

 gallery around the cambium of the tree, thus cut- 

 ting off the food supply which is made in the leaves 

 of the tree, from the lower portion of the tree, 

 namely the roots. Since the roots cannot live with- 

 out nourishment, the tree dies. As soon as the 

 larvae have completed their development they pu- 

 pate. Later they develop into adult beetles. 

 These adult beetles issue forth in swarms the fol- 

 lowing spring, to attack new trees. 



