SOAP SOLUTIONS AND EMULSIONS, 333 



found that a 5 per cent solution of whale oil soap was quite sufficient to 

 kill the larvaj of all species of cochineals, whilst the young and the 

 adults still resist. Eitzema Bos believes that cochineals can only be 

 exterminated by destroying the larvae. With dilute solutions applied 

 even in summer on the trunks, the drawbacks resulting from the use 

 of concentrated solutions are obviated. Solutions of soap and amyl 

 alcohol, those which contain insecticides, are all used for the destruction 

 of cochineal ; they behave like solutions of pure soap but act in weaker 

 solutions. 



Thrijjs cerealium (thrips of grain crops). — Quaintance advises 

 spraying with 0-5 per cent solution of whale oil soap. 



Tetranchus telarius (red spider). — Stone, Fernauld, and Waugh 

 recommend a mixture of sulphur and soapy water to destroy this, 

 acarus. 



