328 WEST VIRGINIA EXPERIMENT STATION. 



in large glass jars with pieces of bark, where they were left for 

 a sufficient time for the females to become fertilized. They 

 were then placed in vials and forwarded to the distributors 

 with orders to place them on the infested trees with the least 

 possible delay. This method of liberating fertilized females 

 offered the most favorable opportunites for the species to estab- 

 lish itself in the localities into which they were introduced, and 

 if all other methods failed this one certainly must have suc- 

 ceeded. 



THE CARRYING OUT OF THE PRIMARY OBJECT OF THE IMPORTATION OF 



THE CLERID INTO AMERICA PREVENTED BY THE DISAPPEARANCE 



OF THE DESTRUCTIVE PINE BARK BEETLE. 



The primary object of the importation of the beneficial Cler- 

 ids was to experiment with it as an enemy of the destructive 

 pine bark beetle, and to secure, if possible, its co-operation 

 with other enemies, in reducing the numbers of the bark bee- 

 tle so that it could no longer overcome the insistence to its at- 

 tack exerted by living trees, and thus bring the trouble to an end. 

 The sudden death or disappearance of all examples of the bark 

 beetles throughout the infested area in 1893, and the almost as 

 sudden ending of the trouble which had been caused by this 

 insect, rendered it impossible to continue the experiment as 

 originally intended. The best opportunity of establishing the 

 Clerid in our forests was thus lost, since the conditions found 

 in the enormous amount of standing, dead and dying timber 

 which was infested by countless millions of examples of the de- 

 structive species and many other species of bark beetles were 

 as favorable for the breeding and multiplication of the Oierid 

 as could possibly have been desired, With the sudden change 

 in the conditions, however, it became necessary to avail our- 

 selves of the next best opportunity for establishing the species 

 in our forests, and attain, if possible the secondary object of the 

 introduction namely, to get it to feed upon the bark beetles 

 common to the bark of injured, dead, or felled trees. By this 

 means it was thought that it could multiply and be ready to 

 meet any subsequent invasion of destructive bark beetles. 



