378 NEW YORK STATE MUSEUM 



adult galleries and that each one contains a number of minute notches, the 

 egg chambers. Each branch represents the work of a female and all have 

 origin in a central chamber near the entrance of which the male stands 

 guard. 



A more advanced stage of this insect's work is shown at plate 62, figure 

 3, which represents the work of three females diverging from a common 

 chamber. It will be seen that a number of the eggs have hatched and that 

 the larvae have worked to a considerable distance in a direction nearly par- 



Fig. 83 Split twig showing girdling by adult Fig. 84 Galleries of Tomicus bal- 



galleries of Tomicus balsame us same us showing pitch chamber, pupal 



(author's illustration) cell in sapwood and work of young 



M o n o h a m m.u s larva (author's 



illustration) 



allel with the wood fibers The eefo- notches are also visible. The same 

 gallery as it appears on the bark is represented at plate 62, figure 1. It 

 will be seen that in this instance at least, the larvae bored in the sapwood 

 rather more than in the bark. A still more advanced stage is shown at 

 plate 62, figure 5, which represents a portion of a trunk which had been 

 injured by a large number of the beetles. The adult galleries, egg notches 

 and the work of larvae or grubs can all be seen. 



Plate 62, figure 4, represents a portion of a very badly infested trunk 



