259 



the wood beueatli the burrow and causing the bark above it to crack. 

 Tlie accidental joining- of a number of tliese galleries may girdle the 

 tree, which then dies. When only a few larvje infest it each year the 

 tree dies gradually, the area available for the supply of sap being 

 reduced from season to season. Dr. Smith has found tliat vigorous 

 trees like the Kiefler will repair damages for some time, but that even 



Fig. 26. — Work of Ar/rihis sijuiaHis \n bark of pear; about one-sixtli natnral size. (After Smith.) 



these succumb at last. The excellent illustration of the work of this 

 destructive larva, which we present (Fig. 26), has been loaned us by Dr. 

 Smith, and is reproduced from a photograph of a Seckel pear tree at 

 the point of branching, the bark being remove<l from the trunk and 

 one of the branches to show the galleries. Tlji3 tree, he says, was 



