p. R. AwATi 269 



(c) Ejfecis : 



(1) It has not penetrated the buds at all. 



(2) None of the larvae were touched by it. 



(2) Paraffin Emulsion, 

 (a) Ck^tn position : 



Paraffin . . . . . . 2 gallons. 



Bar soap . . . . . . | lb. 



Water . . . . . . 1 gallon. 



Diluted 1 gallon to 9 gallons water. 



{b) Action. The fluid is sprayed into minute droplets spread over 

 the surfaces of the leaves — each droplet consisting of two parts — the 

 central core of paraffin surrounded by the outer crust of soapy water. 

 The water then evaporated, and the paraffin core being exposed spread 

 over the surface and the larvae touched by it are killed. The paraffin 

 acts as a contact poison. It has nothing to do with respiration. Thus 

 its action is quite different from that of rosin wash. This is shown by 

 the fact that the larvae do not die as long as there is water, but they do 

 so when the water evaporates and the paraffin spreads. 



(c) Effects: 



(1) If used in excess it burns the plants, especially on a bright 

 sunny day. 



(2) More than 50 per cent, of the nymphs were killed. 



(3) It did not wet evenly. Some drops were resting on the hairs 

 of the bud leaves. 



(4) Nymphs were not wetted on the lower surfaces of the leaves. 



(3) Soap-Creosote Emulsion, 

 (a) Composition : 



100 gallons of water. 

 10 lbs. of (soft) soap. 

 Quart creosote oil (crude, commercial). 



I found this emulsion the best of all. Not only is it simple and 

 effective, as it will be presently seen, but it is the cheapest thing on the 

 market. One hundred gallons of the wash only cost 2s, 6d., and this 

 price compares favourably with any insecticide available. 



I started first of all with the soap solution only, but the results, 

 though not poor, were not very satisfactory. I have already explained 

 why the soap solution by itself is not effective. There is another 

 possibility that the larvae recover the next day. They can withstand 

 suffocation for many hours, and the soap, unlike rosin, does not 



