ON THE HYLOBIUS ABIETIS OR FIR WEEVIL. 75 



about four inches long put into each box ; in a few days the bark 

 was almost entirely peeled off'. On the twelfth a small piece of 

 larch and one of Scots fir were placed in each box, and by the 

 18th it was found that the Scots fir was completely peeled, while 

 the larch was intact. The feeding was continued till 10th 

 November at intervals of about a week, with larch, spruce, and 

 Scots fir separately, and occasionally two of the kinds together ; 

 in every instance a decided preference was shown for the Scots 

 fir. On the 10th of November it was observed that one of the 

 old H. cibictis was dead, and the remaining four died previous to 

 or on 10th December. The three young ones survived till about 

 the 28th of February 1878. It may be remarked, however, that 

 no food was supplied to the insects from 10th November 1877, 

 for the special purpose of ascertaining how long they could exist 

 without it. It must be borne in mind that they were in confine- 

 ment, and not in their natural state. 



It is probable that the H. abieiis hatched in the spring or 

 summer of one year, passes the winter in a semi-dormant state ; 

 re-appears in the following spring, lays its eggs, and dies in the 

 autumn or early winter months ; its term of life extending to 

 fifteen or eighteen months. 



3. Prevention. — From what has been said, it may be gathered 

 that the H. abietis is to be met with principally, if not entirely, 

 in presently existing plantations. It is there it gets its food, 

 lives, and breeds ; and it is on ground where fir trees (larch, 

 spruce, and Scots fir) have lately been cut down and a young 

 plantation formed, that its ravages are chiefly to l^e feared. It 

 cannot be supposed that it would be found, say on natural 

 pasture or heathery ground, as it could not exist ; and it is on this 

 principle the reporter would recommend, as the natural and 

 effectual preventive against damage from this insect, that all 

 ground formerly a fir or mixed plantation, and which it is 

 intended to replant with firs (larch, spruce, and Scots firs) should 

 be allowed to remain unplanted for at least three years on this 

 account alone, and entirely apart from the question of the 

 advisability, on other grounds, of early planting. As a result of 

 the want of food, the insects must either migrate or die ; the 

 older and stronger will probably find a lodgment in some other 

 plantation, but it can readily be conceived that many of the 

 young ones will be unable to obtain suitable food at the time 

 when it is most required, and will die. It might be thought that 

 if this be the case, planting could be prudently commenced in 

 a year or so after the removal of the old trees ; but it must be 

 remembered that there will be many insects in the various stages 

 of development, and eggs to be hatched, remaining on the ground, 

 so that the time specified appears to be a safe one. In the 

 interval between cutting down and replanting, the branches and 



