46 INDIAN FOREST INSECTS 



Again, a large number of insects pupate amongst the dead leaves on 

 the forest floor, or in the humus layer, or in the first inch of the soil. Many 

 root-feeding grubs, of which there are a number of pests, may also be found 

 here. Or the insects lay their eggs here. Methods of destroying these in 

 the forest differ from the ways in which we can attack them in the nursery 

 and plantation. 



(I) Bark- and Wood-boring Beetle Pests in the Forest.— I have already 

 alluded to the fact that serious attacks of bark-boring beetles, Scolytidae, 

 and those of Buprestidae, Cerambycidae, and Curculionidae have already 

 been experienced in parts of India, and practical measures have been put in 

 force to combat them. The following proposals for combating attacks of 

 these pests are based on the practical experience gained in actually carr}'ing 

 out such work in India, and prove that this work is not onl}- possible, but 

 amply repays being undertaken. 



The methods to be briefly described here presuppose a knowledge of 

 the life histories of the pests which have to be dealt with. The measures 

 apply equalK- to infestations in hill and plains forests. 



Assuming that a serious attack of bark-boring beetles is taking place 

 in the forest, this may be accompanied by either a buprestid or a ceram- 

 bycid one, or both. In some cases a weevil, such as the Cryptorhynclms of 

 the long-leaved pine tree, may also be present. The larvae of these insects 

 feed, for a time at least, in the bast layer. Accompanying these bast feeders 

 you will probably find at least one species of wood-boring scolytid or a 

 bostrychid. These will bore straight into the wood and oviposit there. 



The beetles may be attacking the trees in any one or all of the 

 following conditions : — 



(a) Newly felled or fallen green trees (wind- or snow-breaks). 

 {b) Standing sickly trees. 



(t) Standing green trees in the neighbourhood of a "centre" of 

 infection. 



Accordingly the first step to be taken is to mark down all infested trees,, 

 whether felled or fallen, standing sickly, or standing healthy trees. 



(a) Neudy Felled or Fallen Trees. — The first of these are known and can 

 be easily marked down. The second should be searched for and marked 

 down. This will involve going over the whole area carefully. 



(b) Standing Sickly Trees. — The whole area must be gone over and all 

 infected trees found should be noted and marked with a tar ring. It is 

 not to be expected that the whole of these trees will have been found in time 

 to catch the next generation of the beetle to issue after the attack was 

 first discovered. If this generation is not caught it should be possible to 

 mark all the trees down in time to catch the larvae of the second or third 

 generation. 



In the case of (a) and (b) the stems or trees will be left in the forest 

 until thev are known to be full of grubs according to the data given under 



