315 HYPSIPYLA ROBUSTA, MOORE. 

Provinces (Lucknow and Dehra Dun), Bengal (the Duars) and 
Madras (Nilambur), I have found it common in Bengal where- 
ever the tree exists. 
Hampson gives Simla, Dharmsala, Sikhim, Ceylon as the 
distribution. 
Relations to the Forest. 
Both young and old tun trees and also coppice shoots are 
most seriously injured by this pest. In the case of old trees, the 
shape and shade density of the tree is greatly interfered with 
as year after year the young twigs die down under the attack. 
This is very apparent in tin avenues. In many parts of Bengal, 
and more especially on several tea gardens where the tree has 
been planted in avenues to shelter the roads, I have noticed 
that the trees, under the persistent attacks of this borer, have 
grown up straggly and rugged in growth, the object for which 
they were planted being greatly impaired by the insect. Fur- 
ther, the branches being weakened appear to suffer severely 
in storms, a tin avenue being generally littered with branch 
wood after high winds. I do not consider that the tree planted 
pure is to be recommended as an avenue one. 
In addition tothe small branches, the seed crop suffers 
severely from the pest,and in bad years the entire crop is 
sacrificed, the bunches of fruits containing no seeds, but con- 
sisting simply of empty shells each with a round hole on one side 
of it. 
With young saplings and coppice shoots the attack is even 
more serious, Since terminal and side shoots over a foot in 
length turn brown and wither, their interiors being entirely 
eaten out by the burrowing larve The trees thus become 
forked and much branched at an early age, and the height 
growth is interfered with and short ill-shaped and ill-grown trees 
are the result. : 
Protection and Remedies. 
It is generally difficult to prescribe remedies for insects whose 
whole life history is still unknown, and this one forms no 
exception to the rule, We know when and where to find larve, 
pupz, and adults of both generations, but where the eggs are 
deposited is stillunknown. It is necessary to find out where 
