334 WEST VIRGINIA EXPERIMENT STATION. 



mines directly through the bark occupied by the galleries of the 

 destructive bark beetle. Hence, if the young of these beetle 

 have not already developed into adults and vacated, they are 

 in this manner destroyed in great numbers. 



In looking for enemies of the bark beetles, I have found a 

 number of larvae and adults of a Clerid ( Thanasimus dubius) 

 which previous to this time had been rarely met with, as I was 

 then contemplating the introduction of a near relative of this 

 species from Europe, I observed closely its habits, a knowledge 

 of which I realized would be of value to me, both in giving in- 

 structions to collectors in Europe and in readily finding the 

 species, if I should visit Europe for the purpose. 1 found the 

 larvae under the bark where it played havoc with the eggs, 

 larvae and pupae and even young adults of the bark beetle. 

 1 also found larvae in their recently constructed pupae cases 

 in the outer bark, and the adults on the outside running on the 

 bark and snapping up the beetles, and also in its hiding places 

 under the flaky bark near the ground, all of which information 

 proved subsequently, to be of especial value to me. What I 

 learned here, together with that from previous observations on 

 the habits of this species, was in fact, the secret of my success 

 in finding the European Clerid so soon after I arrived in Ger- 

 many. I felt confident that the European species would be 

 found in the same stages of development and under practically 

 the same conditions as was the American one, since by compar- 

 ing specimens of the adults with examples of the foreign 

 species received from Mr. Eichhoff, I fonnd that they were very 

 nearly related. They are also of the same size and color except 

 that the European species has a black head, while the Ameri- 

 can one has a red head. The fact that they were nearly related 

 also led me to believe that the European species would readily 

 adapt itslf to the change of country. The fact that Euro- 

 pean species of insects when introduced into this country breed 

 more rapidly than native species, are more aggressive, and as 

 in the case of the cabbage butterfly, crowd out and take the 

 place of native species, led me to feel confident that the intro- 

 duction of the European Clerid would result in much good. 



