58o 



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 is chieflv 

 Damage Committed j^^^j^^f^-j 

 in 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 



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



This curious raggedness in the shape of the tree is even more marked 



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



manner must seriouslv interfere with and retard their growth. 



Fig. 364. — A \"Mn;; '-'■([. IicmLii- SMplini,' wiUi tup 

 girdled 16 in. down by ■Sco/ylus deodara^ Steb, 

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



