INJURIOUS INSECTS, FUNGOUS DISEASES, ETC. 185 



ends of the branches and small twigs where the newly 

 hatched larvae are found. The work done, however, was 

 effective, as the caterpillars that would have matured by the 

 following spring were killed and thus the deposition of eggs 

 for another brood was almost entirely prevented. In the 

 summer of 1910, when the overwintering larvae began their 

 borings farther down the trees, the work of killing these 

 was carried on in the same way as during the summer of 

 1909. In that way the entire brood of borers was extermi- 

 nated as thoroughly as it was possible. 



Sugar Maple Borer {Plagionotas speciosus Say). Sugar 

 maples on streets and roadsides have no more serious en- 

 emy than the sugar maple borer, which, unlike other borers, 

 attacks trees in full vigor. Like the leopard moth this 

 insect takes two years to complete its growth. At the end 

 of the first season the larva is partly grown. It passes 

 the winter in that condition, resumes feeding and growth 

 the following summer, hibernates as a full grown lar- 

 va the second winter, and in the spring after that changes 

 into a pupa and then emerges as a beetle. 



Constant watchfulness is needed to detect the presence 

 of this borer. Each fall and spring sugar maples should be 

 examined for characteristic signs of borings. The pest can 

 be exterminated in the same way as the leopard moth. 



Maple Tree Sesiid (Sesia acerni Clem.). This is another 

 caterpillar borer found in soft and hard maples. It has a 

 special fondness for tissues growing over wounds in which 

 it makes round holes not over one-eighth of an inch in di- 

 ameter. Trees wounded from any causes find difficulty in 

 covering the exposed wood with bark after being attacked 

 by this insect. 



The injuries caused by this borer are not so serious as 



