AGRICULTURAL ENTOMOLOGY. 2P.7 



The slide now before you is a photograph of a stump of a four year 

 old poplar tree, cut down the middle to show how it lias been tunnelled 

 in all directions just above the ground by an insect. This insect is 

 the caterpillar of one of the clear- winged moths allied to, but distinct 

 from, the well known poplar borer of Europe. According to Mr. 

 Cleghorn, who discovered the insect, a very large proportion of the 

 poplar trees around Quetta are attacked in this way, the result 

 beiug to throw back their growth by several years. Now as the 

 poplar is the chief timber tree of Baluchistan, Avhere it takes the place 

 of the bamboo of Bengal, this means a very serious loss to the 

 country. The caterpillar chiefly chooses young trees for its attack 

 and kills a very large proportion of them down to the ground. The 

 tree then throws out fresh shoots from the roots, and though these 

 may in their turn be attacked, yet some of them usually survive to 

 form a fresh tree. On the screen you now see figures of the cater- 

 pillar, chrysalis, and moth of the insect. Also the curious nest-like 

 structure in which the chrysalis is formed. The life- history of the 

 insect has not as yet been completely traced, but sufficient evidence 

 has been collected to make us conclude that it is as follows : — The 

 eggs are laid in the bark by the mother moth, soon after she emerges 

 in the autumn from the chrysalis. The young caterpillars hatch out 

 from these eggs, and tunnel into the wood, where they remain 

 steadily feeding and growing throughout the whole of the following 

 spring and summer. About September they make a regular nest for 

 themselves close to the opening of the burrow, and then shuffle off 

 their larval skins and transform into chrysalids, so that when the 

 moth emerges in October she has only to push through the thin 

 partition of chips which lie between her and freedom. The colours of 

 the moth are brilliant yellow and brown, and this, in combination 

 with her transparent wings, make her look almost exactly like a big 

 wasp. In fact the resemblance is so deceptive that even when one 

 knows that the insect can only be a moth, which never has a sting, 

 one hesitates to touch her, and this no doubt also prevents the birds 

 from molesting her. For birds, like children, know only too well 

 the unpleasant results of trying to swallow a wasp. 



With regard to remedies there is at present little to suggest, except 

 that in the case of the poplar borer, as in that of the maize borer, 



