284 



WEST VIRGINIA EXPERIMENT STATION. 



brood galleries. The bark on the base of the trunk and on the 

 roots was yet living, which together with the partly dead bark 

 was infested with larger bark beetles, (Dendroctonus tcrebrans.) 

 The bark beetles taken from these trees were subsequently de- 

 termined for me by Mr. W. Eichhoff, of Strassburg, Germany. l 



It was evident to me that some of the insects taken from the 

 bark were to blame for the death of the trees, but of course I 

 could not arrive at any definite conclusions in so short a time. 

 The next day as I was going back, 1 found on another tree that 

 had just commenced to die, and upon discovering a number of 

 the turpentine bark beetles 2 in the living bark at the base, I 

 was inclined to believe that this insert was, possibly, the one to 

 to blame for the trouble. 



A considerable number of dying trees were observed on the 

 mountains in this county sufficiently common, indeed, to indi- 

 cate that it was an unusual occurrence. 



Not having the opportunity to conduct further personal in- 

 vestigations of this trouble during the summer and f;ill of 1891, 

 I had to rely upon what information I could obtain from corre- 

 spondence. 



CORRESPONDENCE. 



In September I received a letter with specimens of insects 

 from Mr. J. S. Strayer, in which he said : 



"I send by this mail a lot of bugs and grubs, secured from a large 

 white pine growing in a private yard and entirely isolated from any body 

 of woods whatever. There are about a do/en large forest trees growing in 

 this yard, amongst the number three or four very tine specimens of /</<//,<; 

 pine. The balance of the trees are oak, and common park trees, locust, 

 etc. One of these pines is rapidly dying. In fact, has died, except the 

 lowest branches which are still green. I examined ihe tree closely, and 

 found rosin exuding frem a thousand or more little holes. Securing a 

 hatchet, I cut through the bark and secured the specimens herewith en- 

 closed. The red head bug I found tnnli-f // l,<irk, but it is possible for it 

 to have gotten there after I cut in. The others, bugs and larvae I found 

 just under the skin of the bark. I send a couple of bugs in the hark as 

 they were when I got them." 



In my reply, October 3, 1891, I said : * * * The small beetles !>- 

 long to the genus Tomicus. * * The red-headed hug * * is a hene- 



1 Colydium lineola. Say., Dendroctonus f>/-t:f>rans. Oliv.. J>< mlroctonnx fronhilix, Zimrn, 

 Pityophthorusconnnis. (?) Lee.. Tomicu* <:<icograp/t,ug,~Leu., Tomicus calligraphu8 t (Jerm., 

 Cossonus corticola, Say, Pissodes strobi, Peck. 



2 Dendroctonus terebrans, Oliv. 



