120 PROTECTION OF WOODLANDS. 



will recommend exterminative remedies being applied in one or 

 other of these special directions, yet, at the same time, the more 

 important and successful of these measures may be considered and 

 criticised generally, in order to a have better overlook, and a more 

 comprehensive idea of them, as well as to avoid the necessity for 

 repetition and reiteration. As, however, such measures are in the 

 case of beetles essentially different from those adopted in the case 

 of moths, it appears advisable to consider them apart in relation 

 to these two different orders of insects. 



(a.) Beetles (Coleopteraz). 



The chief means of annihilating many of the injurious bark- 

 beetles (Scolytidce) and weevils or rostral-beetles (Curculionidte), 

 breeding in conifers, consist first of all in the immediate felling 

 and barking of all stems attacked, and in at once burning the bark, 

 in the cambial layer of which are contained the ova, larvae, pup, 

 and often the recently developed imagines themselves. All stems 

 that are infested should be found out by frequent revisions of the 

 crops, either by the foresters or by woodmen specially trained 

 to the work. Such inspections, however, are not of themselves 

 sufficient, but should be supplemented by laying down decoy- 

 stems here and there (vide par. 60), in as large a number as is 

 convenient, in order to induce the insects to select these for ovi- 

 deposition, and then destroying the brood, a measure that is 

 not only remedial, but also preventive. 



The felling and preparation of such decoy-stems should be seen 

 to early in the season, before the swarming of the insect takes 

 place in threatened localities, for experience has shown that 

 many genera of the above-named classes are most likely to select 

 as their breeding-places coniferous stems with suspended flow of 

 sap ; they therefore seek first of all for recently felled timber, be- 

 fore proceeding to attack healthy trees, whose strong exudation i 

 of resin threatens the well-being of their brood. In localities 

 where, or under circumstances in which, experience has previously 

 shown that the appearance of such insects is to be feared, a 

 suitable number of stems should be felled and formed into decoy i 

 breeding-places ; at the proper time later on in the summer, the 

 same operation should afterwards be repeated, in order to ol>\ into 

 the danger that may arise from a second generation within the 





