516 FAMILY SCOLYTIDAE 



(b) To maintain the supply of edible seed for the surrounding population. 

 On account of the edible qualities of its seed the chilgoza is a most 

 valuable tree, and this fact would not seem to have been fully realized in 

 the existing reports on these forests. The question of the timber is 

 alluded to, and the demand or want of demand for the latter article is 

 discussed. This demand should not seriously affect the question, for only 

 dead wood will be removed. The value of the forest is due to the edible 

 nature of the seed, and is obviously enhanced by the fact that no trees, or 

 very few, need be inaccessible so far as the collection of their seed is 

 concerned. Were this collection done in a thorough and systematic 

 manner, it would be found that the value of the forest in this respect 

 would be thirty to forty per cent, greater to the village communities than 

 it is at present, whilst at the same time seed would be available for 

 regeneration purposes. 



From the life history detailed above, it will be obvious that the bark- 

 borer is able to kill off the trees once it has got a firm hold of them, and 

 when favoured by a succession of dry, hot seasons. The feature of the 

 attack of 1900-1905 was the high proportion of trees affected, and the even 

 higher percentage of infested trees which succumbed to the beetle. The 

 investigations carried out in November 1905 definitely proved the fact that 

 the insect passes through at least three generations in the year and a partial 

 fourth. But for the operations introduced by Colonel G. Chevenix-Trench, 

 C.I.E., to combat the insect, it is certain that an even higher proportion 

 of trees would have been lost. These operations, accompanied by a greater 

 rainfall in the years 1907 and 1909, enabled the attack to be completely 

 stamped out in the Shinghur Forest. The point to be insisted on in the 

 case of this insect, therefore, is its power of killing the trees if left 

 unchecked, and the possibility of stamping out an attack if the beginnings of 

 it are recognized in time, and methods to combat it are introduced at once. 



In his report on the Shinghur Forest, written after a visit in the winter 

 of 1892, Mr. Elliot wrote : " Many trees are dead, the cause in some cases 

 being fire, in others probably the severe conditions of life, considerable 

 heat in summer, great cold in winter, high winds at all times, and scanty 

 rainfall." Mr. Downe in a note on a visit paid in 1900 quoted this state- 

 ment. It cannot, however, be borne out by the true facts of the case, 

 which were indelibly inscribed on the trees themselves in 1905. 



The most serious point about this bark-boring-beetle attack is the 

 fact that the chief pest will infest indiscriminately both healthy and sickly 

 trees. The Scolytidae usually confine themselves to the latter, only 

 attacking the former when driven to do so by a shortness in the supply of 

 trees reduced in vitality. The chilgoza Polygraphus is a marked excep- 

 tion, and as such must be considered as forming a most serious menace to 

 the forest, and not only to the forest at Shinghur, but to the neighbouring 

 ones at Sherghali, the Takht, and Spiraghar. 



I think this Polygraphus also infests the P. gcrardiana in Bashahr. 



