68 DDT — Killer of Killers 



bear labels approved by the U. S. Department of Agriculture 

 or the Agricultural Departments of the states, one can feel 

 certain today that the claims for a particular product are hon- 

 est ones. Therefore, the best advice is: read the label be- 

 fore you buy, and read it carefully, j&ne type and all. 



Shop around in your favorite stores and see how many 

 different types of DDT formulations you can find. If you 

 study carefully, you will find that they fall into the follow- 

 ing classifications: (1) Household sprays, which are solu- 

 tions of DDT and perhaps other insect killers in petroleum 

 solvents, usually deodorized kerosene. These are of two 

 types: residual sprays, with DDT contents of 5 or 6%; and 

 space sprays, containing about /4 to 1 % DDT. These are 

 the common sprays used against the fly, mosquito, and other 

 pests that like to share man's abode. (2) Aerosols. These 

 are little metal bombs, usually containing 3 % DDT and 2 % 

 pyrethrum extract dissolved in a very volatile solvent. When 

 the valve of the bomb is opened, an extremely fine spray mist 

 shoots out and kills all insects — principally flies and mosqui- 

 toes — that it hits. ( 3 ) Household powders, usually made 

 up of 10 % DDT and the rest talc, pyrophyllite, or some other 

 inert extender. These powders, which are so effective against 

 bedbugs, fleas, ants, and other crawling insects, may also 

 contain pyrethrum or other lethal agents. (4) Emulsi- 

 fiahle solutions. These are concentrated solutions of 25 or 

 30% DDT in organic solvents and dispersing agents. For 

 use, they are mixed with water to prepare emulsions, of about 

 2% or 5 % DDT, for the control of flies and other insects in 

 barns, poultry houses, and other outbuildings, and on cattle, 

 horses, and other farm animals. They are also used for the 

 control of various insea pests on agricultural crops, forest and 

 shade trees, and other vegetation. ( 5 ) Wettahle powders, 



