INSECTS INJURIOUS TO SHADE TREES. 83 



In fact, the sort of treatment outlined in the above para- 

 graph may be adopted against borers in general. Sometimes, 

 when sawdust is noticed coming out of an opening, the injec- 

 tion of disulphide of carbon is indicated, plugging up with 

 putty after the injection to prevent the escape of the fumes. 

 C'arbon disulphide may be injected with a syringe, or even 

 the ordinary pipette with rubber bulb such as is used in fill- 

 ing fountain pens. I have a long glass tube drawn to a 

 point, with a large rubber bulb at the squared end, which 

 answers perfectly. It needs only a half teaspoon to a tea- 

 spoonful in any case. 



Flat headed borers and bark beetles prefer trees that are 

 weak or sickly and, in a general way, it pays to keep trees in 

 vigorous health because of their smaller liability to borer in- 

 festation. When a tree is once badly infested, especially 

 with bark beetles, the sooner it is cut out the better. It is 

 simply a source of infection to its surroundings. 



Hickory, and still more often Locust, is very subject to 

 the attacks of round-headed borers, and these attack perfectly 

 sound trees. 



LOCUST BORER. 



The work of this insect is very common on the black or 

 yellow locust in IS r ew Jersey, making it an almost, impossible 

 tree. As soon as a tree attains a moderate size 

 IT is apt to be riddled with the large holes made i>iack locust 

 by the larvae and leads but a sickly life, if it 

 does not die within a few years. 



The beetles themselves are rather attractive creatures, 

 about three-fourths of an inch long, of a dull black color, 

 brightly marked with golden yellow, and may be found fre- 

 quenting the flowers of the goldenrod. In September these 

 beetles gather on the locust trees and mate, after which the 

 female deposits her snow white eggs in cracks and crevices. 

 These soon hatch and the grubs bore into the bark feeding on 

 the soft inner substance. During the winter they are torpid. 

 In spring they resume feeding, boring through the sapwood 



