260 



THE MONTHLY BULLETIN. 



(Fig. 74). The presence of the pest is easily detected, from the fact 

 that the feeding insect is continually shoving out frass from its burrow. 

 From the open wounds the tree also discharges a dark sap-like sub- 

 stance, which discolors the trunk to a large degree. This condition 

 of the bark surface is in itself a very good indication that there are 

 present carpenter worms or some other disturber that should be attended 

 to. In trees Avhere the injury has been present for a period of years 



Fig. 74. — A large live-oak nearly de- 

 stroyed by carpenter worms. Note the 

 characteristic Injury to the trunk and also 

 the depth into the heart wood attained by 

 the feeding larvje, the burrows of the latter 

 showing quite distinctly in the large limbs 

 that have been removed. (Original.) 



(Fig. 74) the tree trunks invariably become decidedly irregular and 

 galled from the unsuccessful efforts undergone in attempting to heal 

 over the many small holes. 



LIFE HISTORY. 



The life histor,y of many insects is often very short, the entire cycle 

 being compassed in a few short days or weeks at best. This is not the 

 case, however, with the carpenter worm. According to the observations 

 of Prof. S. B. Doten of the University of Nevada Experiment Station, 

 nearly three years are required for the development of the larva before 

 pupation takes place, and the emergence of the adult. 



