THE MONTHLY BULLETIN. 



37 



CALENDAR OF INSECT PESTS AND 

 PLANT DISEASES. 



By E. J. VosLER. 



[Under the above heading the author aims to give brief, popular descriptions and 

 methods of controlling insect pests and plant diseases as nearly as possible just prior 

 to or at the time when the suggestions given should be carried into effect by the 

 growers.] 



The Peach Twig Borer. 



The principal liosts of the peach twig borer are tlu; peach, plum, 

 apricot and the aliiiOTid. The larvas of this insect bore into the young 

 buds and tender slioots, and later on enter the fruit at the stem end, 



^ ^^ 



Fig. 20. — The peach twig borer. Top: 

 a, limb showing location of the hibernating 

 quarters ; b, chimneys thrown up in con- 

 structing the hibernating quarters, en- 

 larged ; c, larva in its quarters ; d, larva 

 enlarged. Bottom : a, young shoot killed 

 by the larva ; b, larva ; c, pupa ; d, pos- 

 terior tip of pupa. Lines show natural 

 sizes. (After Marlatt, U. S. Dept. Agric.) 



often completely encircling the pit and rendering the fruit unsalable. 

 The worm that is found so commonly boring into the hulls of almonds 

 while still on the tree is the larva of the twig borer. 



The larva or worm varies in color from a dusky white to a brown, the 

 head and the first three segments being of a blackish color. It is about 

 one-half inch in length when full grown. 



