II 



will generally restore the trees to health, even in case of severe 

 attacks of thrips, it may probably follow that spraying will be 

 resorted to only in orchards favourably situated, and then only 

 to serve as a check on the pest while the results of manuring, 

 draining, forking, and pruning are being developed. 



Insecticides with directions for preparing them, were given in 

 the Appendix to Lefroy's report (West Indian Bulletin, Vol. II, p. 

 185) but may, with advantage, be reproduced for general infor- 

 mation :— 



I. Rosin Wash. 



Powdered rosin ... 4 lb. 



Caustic soda (77 per cent.) ... I " 



Fish oil ... f pint 



Mix these, cover with about 2 inches depth of water and boil 

 till all is dissolved. Then add water very sloivly to the liquid, 

 keeping it continually boiling until the whole is made up to about 

 3 gallons. This is stock solution. For use, add 6 gallons of 

 water to I gallon of stock solution. 

 Amount of wash, 21 gallons. 



2. Kerosene Emulsion. 



Hard soap ... h lb. 



Kerosene ... 2 gallons. 



Boil the soap in I gallon of water till it is dissolved. Take it 

 off the fire, at once pour in the kerosene, and churn the mixture 

 with a force pump or syringe for ten minutes. This is stock 

 solution. Add Q gallons of water to I gallon of the stock solu- 

 tion. 



Makes 30 gallons. 



3. Kerosene Emulsion with Whale Oil Soap. 

 Use I lb of whale oil soap in place of \ lb. of hard soap as in 



No. 2. 



4. Rosin and Whale Oil Soap Compound. 



Rosin ••• 4 lb. 



Washing soda ••• 3 



Whale oil soap ••• 10 



With the rosin and soda make 4 gallons of rosin compound 

 stock solution as above. Stir the whale oil soap in 5 gallons of 

 hot water : mix the two while hot. This is stock solution. To 

 every gallon add 4 gallons of water. An alternative method is to 

 make the rosin compound stock solution. For use, mix I gallon 

 with 10 gallons of water and stir in 2h lb. of whale oil soap. 

 Every 45 gallons of wash should contain the above ingredients 



however mixed. 



Of these I should recommend Nos. I and 3 as likely to be most 



effective. 



