HOW TO COMBAT THE ATTACK OF INJURIOUS FOREST INSECTS. 9 
thin-barked pines are also attacked, and, worst of all, growing 
trees, especially such as are somewhat unhealthy, are no longer 
safe. Let me cite two instances of a large amount of damage being 
caused by this insect using growing trees for purposes of oviposi- 
tion. In the peninsula of Darss, in Pomerania, on the 12th and 
13th of November 1872, the tide rose exceptionally high, with the 
result that a district stocked with Scots pines was more or less 
inundated. The effect of the sea-water upon the trees was to 
cripple their growth to some extent, and make them tempting 
objects for insect attack. During the next year or two pine 
beetles increased at an alarming rate, and totally destroyed all the 
pines on 2500 acres, 
A similar experience, on even a larger scale, is reported from 
France. In the Department Gironde Pinus maritima is largely 
cultivated, chiefly for the purpose of binding the drifting sands. 
In the hard winter of 1879-80 the trees suffered severely, and the 
pine beetles consequently appeared in enormous numbers. The 
result of frost and insects together was the destruction of timber 
to the value of £1,680,000. 
If any difficulty has been experienced in proving that JZ. 
piniperda is the perpetrator of an excessive amount of mischief 
when in its hibernation or breeding quarters, the task will be all 
too easy when we examine its life-lristory at other times. When 
the young insects hatched underneath the bark have reached the 
imago stage, they desert their birthplace and take to the young 
shoots of the pines, into which they bore, and usually cause their 
death. The damage is most apparent in plantations from fifteen 
to thirty years old, where it is no unusual thing to find that 
quite 50 per cent. of the trees have been deprived of their leading 
shoots again and again, and have been reduced from fine straight 
poles to little better than misshapen bushes. When this happens, 
and I am sure many instances of its occurrence must present 
themselves to your minds, the future prosperity of the wood can 
no longer be looked for, as it can, at the best, only produce poorly 
developed and badly formed stems. 
In old woods the work of the insect in this way is not less 
destructive, if somewhat less apparent. Here, too, the young 
shoots, both of stems and branches, are its feeding ground. Into 
these it bores its way, and weakens them to such an extent that 
they are easily broken off by the first high wind, and litter the 
ground in large numbers, I believe that squirrels are often 
