154 DDT — Killer of Killers 



infested areas, as described above, is very effective for con- 

 trolling fleas. 



FLIES 

 In Buildings 



Space sprays with as little as % % DDT, together with 

 pyrethrum or organic thiocyanates for rapid knockdown, will 

 kill all flies that are hit by the spray mist. 



Aerosols containing 3 % DDT and 2 % pyrethrum ex 

 tract are very Q^Gcdwt space sprays. The extremely fine mist 

 that is evolved while the trigger is depressed remains in sus- 

 pension for a considerable period of time and is carried to all 

 parts of the room. 



Residual sprays containing 5 % DDT in deodorized 

 kerosene are used where long-lasting action is desired. These 

 sprays are applied to the walls and ceilings, screen doors, 

 lamp cords, and other surfaces on which insects light. An 

 invisible deposit of DDT remains after the evaporation of 

 the solvent, and any insects that come in contact with it are 

 doomed, although they may continue to live for an hour or 

 more. The spray should be applied at the rate of 1 quart 

 for every 250 square feet of surface. One application will 

 remain effective for long periods of time — from a few weeks 

 in exposed places up to several months in enclosed areas. 



Emulstfiahle solutions of 25 or 30% DDT can also be 

 used where residual action is desired. These solutions are 

 mixed with water before use to provide an emulsion of 5 % 

 DDT. These emulsions, however, should not be used where 

 water might stain the surface or where the white deposit is un- 

 sightly. For use in barns and other outbuildings where 

 staining and appearance are not faaors that have to be con- 



