CHAPTER XI 



ATTACK ON PROPAGATION AREAS BY LARVACIDES 



T^HE requirements for a good larvacide are: 

 -*■ I. That it shall be of high toxic power, so 

 that a small quantity may suffice for a large volume 

 of water. This reqtiirement is important for its 

 economic use in water lying far from roads and 

 trails. 



2. That it shall kill rapidly, preferably in less 

 than ten minutes, that rain intervening, and con- 

 sequent dilution and weakening, may have as little 

 efifect as possible. 



3. That it be uniform in its toxic power and 

 capable of standardization. 



4. That it shall mix freely with brackish and 

 alkaline waters. 



5. That it be harmless to man, and domestic 

 animals, when in the dilution necessary for larvaci- 

 dal action. 



6. That it shall not be susceptible to rapid 

 deterioration through age, and exposure to the 



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