The Genus Hylastes, Er. 155 
recover. The following is a summary of my examination of a hundred of 
these plants, showing the cause or causes of injury :— 
Killed solely by Hylastes  . . 46 
» by Hylastes and Hylobius a Gites head 
» solely by Hylobius  . ea ty 
, by bad planting 1, 
It may be remarked that the above table sitive a er percentage of 
deaths caused by Hylobius, which is commonly regarded as the source of all 
evil in young plantations. This at first sight appears a just observation, but 
in the area in question spruce stumps predominate, and these, although they 
afford breeding-ground for Hylobius, are not its favourite host, which is the 
Scots pine. Further, the number of Bark Beetles reared in a stump is very 
much greater than the number of Pine Weevils. I have no reason whatever 
to suspect that the hundred plants I selected throughout the area are not quite 
representative of the conditions in it. In fact, I am sure that if I had 
counted the stumps on which I found Hylobius larve and the numbers I 
found on each stump, and also counted the stumps which yielded Hylastes 
and the numbers yielded by each, that the figures would have been somewhat 
more in favour of Hylastes than the above summary shows. The Kaim 
Wood affords an excellent example of Hylastes attack, and it also affords a 
most interesting illustration of misapplied preventive measures. After the 
area was felled and the timber removed, the overseer, Mr Chalmers, caused 
all the brushwood to be burned on the top of the stumps, charring the 
stumps and roots considerably. Either such a precaution is wholly useless 
or it was taken at the wrong time. It was, I believe, taken primarily to 
prevent weevil attack. In this respect it may have been not wholly un- 
successful, but, as regards Hylastes, it completely failed. As I have 
observed, the swarm period’ of Hylastes is not limited to a short period, 
and while the act of charring may have repelled one invasion it has certainly 
not repelled them all. Apart from that difficulty there is this to be considered, 
that H. ater and H. cwnicularius are soil dwellers, and while the fresh stumps 
probably serve to attract them to a felled area they are not the chief breeding- 
ground of the beetles, which is rather the root-system. Brushwood burning, 
therefore, unless it can be so arranged as to char the root-system as well as the 
stump (a very difficult matter), is practically useless as a preventive measure 
against Hylastes. Such a statement by no means condemns that excellent 
practice. H. ater and H. cunicularius are not our only forest enemies, and 
brushwood burning is always justified by the numbers of J. piniperda, 
H. palliatus, P. bidentatus, and other Scolytids it destroys or prevents from 
breeding. 
