IGMCULTURAL ENTOMOWQY 23$ 



offered of this i'ad is that in cases when the cane is growing vigor- 

 ously the insect gets suffocated by the juice which accumulates iu its 

 burrow, so that it is only when the flow of juice is not very vigorous 

 that the insect survives. This therefore points to the utility of 

 irrigation for fields that are attacked, and explains the fact that in 

 fields which are kept clean and are well cultivated the insect does 

 much less damage than in field? which are < lovenly 



manner. Hhis feature is of very wide application in connection with 

 boring insects of ail kinds, and it explains Mime very curious points 

 in connection with insects that bore into wood, notably with the 

 bamboo borer and the sal girder, about these I will tell you at the 

 end of the lecture, if time allows, iu illustration of the fact that, at 

 least in the case of boring insects of all kinds, healthy plants not only 

 recover much more rapidly when the\ have been attacked than 

 unhealthy ones, but are actually much less liable to be attacked in 

 the first instance. Talking of the - which tend to keep down 



this pest, I should naturally pass to the parasites which are sometimes 

 so effective in destroying it, that they entirely defeated the attempts 

 which I made some time ago to rear the moth from sorghum shoots. 

 I must go on, however, to the next insects, as we shall otherwise not 

 get through our pi-ogramme within the hour. 



The next slide is a photograph of a few of the apple twigs, which 

 have been sent to me in connection with the great injury which has 

 been done during the past two years to apple trees in the Xilgiri 

 Hills by a minute insect which proves to be Schizoneura hunger a, the 

 American blight of Europe and the United States. The slide shows 

 the characteristic gall-like growth, which arises both on the branches 

 and roots, from the irritation set up by the insect in feeding upon the 

 juice of the tree, also the fluff -like secretion which serves to protein 

 the insects themselves. For mwra /a nigera, unlike most other 



aphids, has not entered into any defensive league with the ants. The 

 habits of this insect have been observed by Lichtenstein, who found 

 that the winged individuals, like the one which you see on the slide 

 now before you, beget in the autumn the wingless male and female, 

 which do not take any nourishment, and whose only function it is to 

 produce the winter egg. Each female lays but one winter egg, and 

 then dies. The winter egg lies through the winter upon the bark 



