SPOTTED APPLE-TREE BORER. 9 



responsible for the loss of the borers was not determined definitely, 

 but all the evidence pointed to the downy woodpecker, Dryobates 

 pubescens medianus. It seems probable that the spotted apple-tree 

 borer would be a much more widely known and destructive pest 

 were it not for the constant depletion of their numbers by wood- 

 peckers. 



On one occasion a newly emerged female beetle was found in one 

 of the rearing cages hanging suspended in the jaws of a spider. 

 (PL I, D.) The spider was captured and was determined later by 

 Mr. C. B,. Shoemaker as Xysticus ferox (Hentz). 



In several cases in Michigan larvae of the clearwing moth Aegeria 

 pyri Harris were found as the sole occupants of burrows made re- 

 cently by spotted apple-tree borers. There was good reason to 

 believe that the larvae of the moth had devoured the original occu- 

 pants, but this could be considered only as an incidental occurrence. 



METHODS OF CONTROL. 



There is little doubt that in apple orchards which are sprayed 

 with arsenic als for the codling moth and other common insect pests, 

 many of the adults of this borer may be killed incidentally. The 

 fact that beetles feed rather freely on exposed surfaces, especially 

 on the wrinkled baik at the base of twigs where deposits of the 

 poison from sprays collect and adhere, makes them susceptible to 

 this means of control. The beetle has a rather prolonged feeding 

 period before oviposition begins, and this affords a chance to kill 

 it with poison sprays before it has provided for a succeeding genera- 

 tion of borers. 



The borers, while small, may be found and removed from the 

 trees very readily by paring away the bark over their burrows with 

 a sharp knife. The burrows can be located without much trouble 

 by the conspicuous castings which are thrown out, and also by the 

 swollen, cankerlike appearance of" the affected wood. (PL IV, C.) 

 Badly infested branches can often be removed without injury to 

 the tree, and the borers within be destroyed by burning. Breeding 

 places, such as are provided by neglected seedling apple trees, and 

 thorn and wild crab apple thickets, should not be allowed to remain 

 in the immediate vicinity of cultivated orchards. 



