AND OTHEE INSECTS WHICH INFEST CONIFERS. 133 



settling upon their baric, and sucking the juices of the plant till the 

 young wood is literally killed. It spreads with marvellous rapidity 

 over whole trees, and frequently causes total destruction to every 

 young silver fir in a plantation. Young thriving trees of about 

 eight to twenty feet in height appear to be most vulnerable to its 

 attacks. The first appearance of the tree being infested with this 

 plague is to be noticed upon the main stem and under side of the 

 branches and young shoots, where it presents the appearance of a 

 pure white minute substance in small patches close together, which, 

 when microscopically examined, are found to consist of an adhesive 

 cotton-like substance or covering, within which numberless clusters 

 of the eggs of the creature are deposited, and occasionally the insect 

 itself may be found. Gradually the whitened appearance spreads, 

 and with wonderful rapidity the entire bole and branches seem to 

 be dusted over with this downy matter, containing myriads of 

 animals, each busily engaged with its sharp though minute proboscis 

 in tapping the juices of the tree. Their settlement upon any tree 

 will continue for two or three years, till, from first presenting a 

 dwining and unhealthy look, the unfortunate victim falls into a 

 decline from which Nature cannot recover it. The spectacle pre- 

 sented as the progress of decay proceeds is indeed melancholy ; the 

 top branches and terminal shoots die first, and gradually, tier by 

 tier, the handsome branches wither off, and in a very few seasons 

 the tree is killed to the ground-line. This insect never attacks the 

 leaves, but confines its ravages entirely to the bark of the young 

 shoots and bole. 



A nearly-allied species of Bostriclius (B. laricis) is very common 

 upon the larch. It does not, however, prove so fatal in its attacks. 

 This insect is commonly and appropriately called " the larch blight," 

 from the appearance which it gives the tree when first attacked. 

 The eggs may easily be detected concealed in the crevices of the 

 young bark, and in the hollows around the buds, where they abound 

 in winter time, and are easily discernible by the naked eye, like 

 minute round black grains. They propagate in spring with mar- 

 vellous rapidity, covering leaves, branchlets, and stem with a small 

 black covering, which gradually whitens as those creatures weave for 

 a covering and protection from rain, a thick, white, viscid, woolly- 

 like substance from their numerous pores, and which is the cause of 

 that sticky and clammy feeling so well known in connection with 

 the larch tree. Happily, as has already been stated, the ravages of 

 this little creature are seldom fatal, although it lives upon the juices 



