ON METHODS OF PREVENTING INSECT ATTACK 37 



A storm in the Vosges Mountains in 1902 blew down over one and 

 a quarter million cubic metres of coniferous trees in a few hours. A severe 

 bark-beetle attack commenced shortly afterwards, the first lot of beetles 

 being reared in the windfalls. As soon as the windfalls were too dry or 

 had been removed, the beetles went to the green standing trees (silver fir 

 and spruce) in the neighbouring woods, and 14,603 trees had to be cut out 

 and barked before the attack was 

 stamped out ; thus upsetting the 

 working plan. 



And it is not only in coniferous 

 forests that the danger is to be feared, 

 although the trees in these forests 

 do not so readily recover from insect 

 attack as is the case with broad- 

 leaved species. 



India has already had some first 

 experiences of the power of the 

 insect over its tree-host. 



The attack of bark beetles {Poly- 

 graphiis and Phloeodnus) experienced 

 in the Pinus gerardiana forests in 

 North Zhob, Baluchistan, between 

 1903 and 1906, resulted in a heavy 

 loss of valuable trees, and had it not 

 been taken in time might well have 

 resulted in the disappearance of the 

 forest altogether (^fig. 21 and p. 510). 



The Quetta borer {Aiolcsthcs, 

 p. 307), attack practically destroyed 

 the major portion of the beautiful 

 avenues of Quetta between igoo and 

 1905, cost a considerable sum of 

 money to get rid of, and an addi- 

 tional expenditure in replanting. 



Bark-borers {Scolytns and Tonii- 

 cus) made their appearance in the 

 Bashahr State in 1900, and but for 

 the prompt steps taken by Mr. B. 

 Ribbentrop, CLE., at the time 

 Mr. Minniken, who was in charge of the division, a considerable number of 

 deodar and blue-pine trees would have been killed. 



In the Simla Catchment Area a bark-beetle attack suddenly made its 

 appearance early in 1908, and but for the action taken by the Divisional 

 Officer, Mr. V. Munro, and his assistant. Pandit Gokal Dass, Extra-Assistant 

 Conservator of Forests, would have undoubtedly developed into a dangerous 



Fig. 



22. — Egg-galleries of 

 shol>i, Steb., in Pinus 

 bark from North Zhob. 



PJiloeosintis 

 gerardiana 



Inspector-General of Forests, and 



