THE PINE INVESTIGATION. 



Oct. 22, 1893, 1 found a larva evidently of this clerid with larvae 

 of the bark beetle upon which it had evidently been feeding. 

 Elaterid larva. On October 22, 1893, 1 found an Elaterid larva 

 resembling the common wire worm, in the galleries of Dendroc- 

 tonus terebrans feeding on a pupa. 



Diseases. On October 5th, 1893, I found a colony of adults 

 in white pine bark, which had apparently died from a fungus 

 disease. 



Cold. In May, 1893, 1 found that all stages of D. terebrans 

 which occurred in the bark a few feet above the base of the 

 trees had been killed in a similar manner as D. frontalis, 

 which was evidently due to the severe freeze of the previous 

 January. 



The fact that so many individuals of this beetle survived, 

 while all the destructive species was destroyed, is evidently 

 due to their normal habit of occupying the bark near the 

 ground and even beneath the surface in the bark of the roots, 

 while the destructive species occurs only in the bark on the up- 

 per and exposed portion of the trunk. 



Fig. LXXX Species of the genus Tomicus. 

 THE GENUS TOMICUS. 



The scolytid genus, Tomicus, which is the same as Ips of 

 some European writers, is represented in the area covered by 

 the invasion of the destructive pine bark beetle, by five com- 

 mon species out of some ten recognized species in America, 

 north of Mexico. 



They are distinguished by the peculiar concave or flattened 



