l895-] ENTOMOLOGICAL NEWS. 295 



Associated with the injury by the Sro/y/us at Natrona, I found also the 

 exit holes of what was apparently a longicorn, and I found also a few lon- 

 gicorn larvae in wood that was split when the trees were cut down. These 

 may have been Cyllene pictus. In trees that were entirely dead, and from 

 which the bark had been loosened I also found specimens of Tremex 

 columba which had died in the effort to em_erge, and I wa"s not able to 

 decide tiie question satisfactorily whether, as a matter of fact, the Scoly- 

 tus was the first one to attack the healthy trees or whether they had been 

 weakened by some other attack previou>ly. 



In the case of the trees at Glen Ridge, N. J., there was an adequate 

 reason for the attack by insects, since from their situation they had been 

 deprived of moisture and nourishment for a long series of years past, 

 which had probably resulted in greatly weakening them. For the trees 

 at Natrona no such reason could be assigned. To be sure there had been 

 a drought the year before and everything was at the time of my visit suf- 

 fering from lack of rain, but this could scarcely have been sufficient to 

 account for the enormous development of the insect, especially as many 

 of the trees had evidently been attacked several years ago. 



The problem of dealing with insects of this kind is one that is by no 

 means solved, and indeed we are, to a very considerable extent, helpless 

 against the creatures. My observations indicated that there was at least 

 two broods of- the Scolytus in the course of the season, and as we have 

 no insecticides that can penetrate and kill the larvae under the bark, we 

 are reduced to efforts to keep the specimens out, and this is a task by no 

 means easy, considering tlie habits of the insect. It was noticed, both in 

 New Jersey and Pennsylvania, that a great many of the beetles developed 

 about mid-Summer a fondness for boring into young twigs just below the 

 point from which the leaves started, so that here and there throughout 

 the tree, there were little bunches of leaves wilted, which eventually dried 

 and fell to the ground. This is an injury that cannot be prevented, so far 

 as I am able to see, and apparently these short burrows were made by 

 the beetle for food alone, since I never found any attempt to oviposit in 

 such places. But, while the trunks are undoubtedly the favored point of 

 entrance for the insects, yet I found that if there was any reason why they 

 should not lay their eggs there they had no objections at all to even com- 

 paratively small branches. While we may protect a trunk against the 

 entrance of these insects by smears or washes, it is a difficult matter to 

 protect also all the branches, and the subject of dealing with bark boring 

 pests on large trees is one that deserves the careful consideration of 

 economic entomologists. It is in the hope of getting the experience of 

 other students, who may also have observed this insect, that this subject 

 is presented here. The picture illustrates a typical gallery, not quite 

 complete in the picture as shown in the last number, but the form of the 

 central burrow and the method of branching in the larval burrows is char- 

 acteristic, and well shown. This piece of bark was taken from a tree 

 entirely dead, and the tree, which was a large one, nearly eighteen inches 



