THE GENUS DENDROCTONUS. 155 



attack on living trees and on the stumps of those recently felled is 

 indicated by large masses of pitch and pitch tubes, mixed with 

 reddish borings. 



SEASONAL HISTORY. 



OVERWINTERING STAGES. 



The winter is passed in and beneath the bark of trees and stumps 

 attacked the preceding spring and summer, as parent adults, larvae, 

 and developed broods, the larvae, as a rule, occupying the bark on the 

 roots beneath the surface of the ground. 



Fig. 98.— The red turpentine beetle. Egg galleries and larval chamber: A, Incomplete egg galleries 

 with boring dust removed; B, normal gallery; C, advanced stage of work; a, entrance burrow; 

 b, basal section; c, ventilating burrow; d, egg nest with eggs; e, boring dust; /, subsequent or inner 

 galleries; g, larvae at work; h, pupal cell in boring dust mixed with resin. (Author's illustration.) 



ACTIVITY OP OVERWINTERED BROODS. 



The overwintered parent adults begin to extend their galleries 

 during the first warm weather in March, April, or June, depending 

 on locality, and probably continue to work in these, or excavate new 

 galleries, until July and August, or later. It is probable that after 

 finishing one gallery they emerge and excavate new ones, and that this 

 process may be repeated during the summer and fall. It is also not 

 improbable that some of them may pass the second winter. The 

 overwintered broods of young adults begin to emerge from the bark 

 in April and continue to do so during May and June, and less com- 

 monly until August, or later; they excavate galleries principally in 



