5 8o 



FAMILY SCOLYTIDAE 



a branch girdler laying its eggs in the girdled portion of the tree. Since 

 the monsoon bursts on the average about the end of June, the girdled 

 branch would dry less rapidly, and consequently serve as food for the 

 larvae hatching from the eggs for a longer period, if the eggs were laid 

 just before the rainy season, than if they were laid in the early summer 

 when the branch would be exposed to the full rays of the summer sun. 



The only other period of the year at which I have found branches 

 freshly girdled by this beetle is at the end of October. It may be that 

 the trees are girdled some time during August (I have not been able to study 



the insect during that month) 

 by beetles resulting from the 

 eggs laid in June ; and if so, 

 this would indicate that the 

 insect passes through two 

 full generations and a par- 

 tial third one in the year, 

 the partial third generation 

 resulting from the eggs laid 

 at the end of October, the 

 larvae from which either 

 pass through the winter as 

 such or develop into beetles 

 which remain in situ in the 

 branch until the following 

 year. 



This scolytid beetle at- 

 tacks trees of all ages, but 



it ischieflv 



Damage Committed i r "i 



harmful 

 m the Forest. 



t o young 



growth, saplings, and young 

 poles. These it more usually 

 than not attacks at the top, 

 girdling the leading shoot 

 and thus spoiling the shape 

 of the tree. I have seen a 

 sapling which had had its 

 leader and two subsequent leaders (formed by side branches replacing the 

 last leader) girdled by the beetle. 



In large trees its work is also easily recognizable. They may be 

 observed to have a curious irregular shape owing to numbers of the 



3 having had their ends " cut " by this insect. 



. his curious raggedness in the shape of the tree is even more marked 

 :he case of smaller trees, and the number of branches treated in this. 

 manner must seriously interfere with and retard their growth. 



FIG. $64. A young 8ft. Deodar Sapling with tup 

 girdled 16 in. down by Scolytus deodara, Steb. 

 Jaunsar, N.W. Himalaya. (J. W. Oliver, photo.) 



