PrvOCEEDIXGS OF THE THIRD ENTOMOLOGICAL MEETING 



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on insect control in India. Insect control, as we all know, is effected 

 in various ways— there are natural means and there are artificial mean& 

 of control. Insect pests are likewise controlled also by many natural 

 factors— the climate, the nature of the plant attacked, the environment, 

 the presence or absence of parasites, and so on. Now. in dealing witli 

 an insect all these factors have to be taken into consideration and you 

 must be thoroughly conversant with the effect of these on the insect in 

 all stages before you can hope to estimate the value of your control 

 methods and, in view of the practical difficulties which may be experi- 

 enced in applying recognized remedial measures under different circum- 

 stances, it seems to me that general methods of control are very far 

 away and that successful control is a question of adopting a method 

 adapted to each particular instance. • 



Take the case of insecticides. It does not follow that an insecticide 

 which has once been successful will always be so, nor does it follow, 

 because an application of insecticide is ' once ' ineffective, that it may 

 not be used effectively under proper conditions. A case of this kmd 

 can be instanced in connection with the tea mosquito, and it shows the 

 imperative necessity for close observation of the habits of the pest. 

 The tea mosquito can be killed by soap solution or by lime-sulphur if it 

 is kept in them for a sufficient time, but this time is too great to render 

 the substances of much value as an insecticidal application in the ordinary 

 way. Now the tea mosquito has the following habit. It feeds on 

 the young shoots of the bushes in all stages, sitting on the leaves and 

 sucking them. When the bush is disturbed the adults apparently drop 

 to the ground. They do not, as a rule, however, drop quite to the- 

 ground, but drop almost to the ground and then fly away into another 

 bush. The young forms, which cannot fly, run down the stems of the 

 bushes and conceal themselves at the nodes where the leaves or branches 

 come off from the stem. The bush is sprayed, the insects being thereby 

 disturbed. The adults drop and fly away elsewhere and escape the 

 spray ; the young forms run down the stems and branches to the nodes. 

 The fluid falls on to the leaf, runs down the stems and collects m drops 

 at the nodes, and the young insect is caught in a drop of fluid which is 

 too big for him to be able to break through, and is held m the liquid for 

 a sufficient period to allow of his being killed. Therefore, if the insecti- 

 cide is appHed when the bulk of the insects are in the young stages one 

 may have great success with it, and if applied when the majority are in 

 the adult form no success. The result is that of tea planters to whom 

 recommendations of this nature have been made, some say it is no good, 

 while others say that it had excellent results. The fact of the matter is 

 that whereas the substances cannot be recommended for general use 



