98 THE APPLE LEAF HOPPER 



Fig. 43. Larva, pupa and adult of Maple Borer. Original, 



THE BRONZE BIRCH BORER, 



Agriliis auxins Gory. 



The illustration given herewith, Fig. 12, shows excellently the 

 work of this pest. Birches on the Experiment Station grounds have 

 been badly affected, a number dying during the summer of 1908, ap- 

 parently as the result of its work. It attacks the Cut-leaved Birch and 

 both the Yellow and White Birch. It is also recorded from poplar 

 and from willow. 



Borers nearly or quite full grown were taken from White Birch 

 here on September 19th, from trees which were first noticed to be 

 dying about July 15th. In many cases some of the smaller limbs ap- 

 peared to have been killed by attacks of the insect in 1907. From 

 the photograph one will readily see that these borers work just under 

 the bark, practically girdling it, though they also go deeper into the 

 wood. 



The borer winters under the bark in the larval stage, pupating 

 in the spring, the adult beetles emerging a little later, possibly in early 

 June in Minnesota. By the latter part of July and during August 

 young larvae are at work under the bark, their presence being recog- 

 nized by a red color, and indications of the course of their burrows by 

 raised ridges on the bark. The larva apparently may leave the cam- 

 bium layer in the fall and work into the wood, where, in a cavity 

 which it prepares, it passes the winter, pupating the following spring 

 or early summer. The tops of the trees are attacked first, dy'mg as a 

 result of its work ; yet Dr. Franklin reports that "limbs evidently killed 

 the previous year were, as a rule, among those nearest the ground." 



Remedies: The destruction by cutting and burning of all infested 

 trees during the zcinter or very early spring before the appearance of 

 the adults. Do not leave any infested part of the tree standing. 



Dr. E. P. Felt, of New York State, thinks that some of the injury 

 done by this beetle is due to leaving a portion of the trunk standing, 

 enough borers remaining under the bark to carry infestation to other 

 trees. These stumps are sometimes left for the support of flower 



