iINE INVESTIGATION. 



fested with the Scolytids and a few adults of lhanasimus 

 dubius were observed, none were found that could be recog- 

 nized as the imported insect. 



In a paper read at a meeting of the Association of Economic 

 Entomologists, I made the following reference to recent in- 

 vestigations with reference to the conditions previously referred 

 to. 



(Extract from paper entitled Destructive Scolytids and their 

 Imported Enemies, published in the proceedings of the Associa- 

 tion of Economic Entomologists and Insect Life, Vol. VI, pp. 

 123-130, 1893. Read at Madison, Wis. Aug. 20th, 1893.) 



* * * There is one interesting fact, however, that I have observed 

 this season regarding the destructive pine bark beetle Dendroctonus front- 

 alls, and that is its numbers have been greatly reduced since last fall, con- 

 sequently ac this time very little if any timber is dying. 



On the 24th of July, 1892, I found this species attacking and mining be- 

 neath the bark of living trees, 1 in which they occurred in immense num- 

 bers. By the latter part of September, a brood had emerged from the bark 

 of the same tree while the leaves were yet green, and those that had 

 emerged were entering the bark of other living trees. In November the 

 bark of the same trees was found to be infested by countless thousands of 

 the insects in all stages from eggs to adults. Trees so affected subse- 

 quently died, but through persistent search in the bark of such trees in 

 different sections of the State I have failed, as yet this season to find a 

 single living example of Dendroctonus frontalis. Hence the trouble, as 

 caused by this species, is evidently at an end in West Virginia, for the 

 present at least. 



No other species of Scolytids infesting the same trees seem to have 

 been affected by the cause which it would seem has rendered Dendroc- 

 tonus frontalis almost extinct. In fact, the great number of trees that 

 died last summer and fall were found last spring to be infested by im- 

 mense numbers of bark and timber beetles of different species. These 

 have since emerged, and it would seem that the only danger to be appre- 

 hended of a continuation of a trouble like that we have mentioned would 

 be from the attack of some of the species which have thus emerged from 

 the dead trees, for it is evident that unless they find favorable conditions 

 in the felled trees, tops, stumps, etc., in lumbering regions they must 

 either attack and kill living trees or perish, 



One species, the turpentine bark beetle, Dendroctonus terebrans has al- 

 ready made a desperate effort in this direction. Early in May the adults 

 emerged from the trees in which they had bred, but failed to find dying 

 trees, the bark of which they preferred to infest for the purpose of depos- 

 iting their eggs. Then followed a remarkable and interesting occurrence. 



* * * They, with numerous other members of the Scolytid family, in- 

 cluding both bark and timber beetles must have started, with one accord, 

 in search of more favorable conditions for their propagation, for they oc- 

 curred in different sections of the State, at about the same time, in great 

 swarms like migrating locusts. Specimens were sent to us accompanied 

 by startling accounts of plagues of bugs that visited mill yards, furniture 



1 Mayfleld Hill. 



