INSECTICIDES AND REPELLENTS 81 



PROTECTION OF ANIMALS FROM INSECT ATTACK 



A special insecticide formulation has been developed for protecting 

 pack and other animals from attack by insects. It is an emulsifiable 

 concentrate containing, by weight, 5 percent of pyrethrins, 25 percent 

 of piperonyl butoxide, and 10 percent of emulsifier in deodorized kero- 

 sene. 



Pack animals should be sprayed or sponged with an emulsion 

 containing 1 part of the concentrate to 50 parts of water. For 

 treating one animal to prevent attack by flies, add % ounce to 1 quart 

 of water and mix by snaking. About 2 quarts is required to wet an 

 animal sufficiently to control lice or ticks. 



This treatment will protect animals from attack by stable flies, 

 horse flies, and deer flies for 2 to 3 days. If the animal is working 

 and sweating profusely, daily treatments may be required. For 

 tick protection weekly treatments may be sufficient. For louse 

 control two treatments 2 weeks apart are recommended. 



TOXICOLOGY OF INSECTICIDES AND REPELLENTS 



An important phase in the development of chemicals for controlling 

 insects is a study of their toxicity to appraise the hazard to man, 

 domestic animals, wildlife, and beneficial organisms of all kinds. The 

 nature of the hazard obviously depends on the manner of use and the 

 length of time and degree of exposure to the chemical. Many agencies 

 and individuals have contributed to our knowledge on the toxicity 

 of insecticides and certain repellents. The information obtained has 

 made it possible to select safe materials. Many effective insecticides 

 and repellents are not recommended for specific purposes, because 

 they are too hazardous or insufficient information is available to 

 determine if and how they may be used safely. 



During World War II the Division of Pharmacology of the Food 

 and Drug Administration and the Industrial Hygiene Laboratories 

 of the National Institutes of Health investigated the toxicity of promis- 

 ing insecticides and repellents that were being developed for the mili- 

 tary services at the Orlando and Belts ville laboratories. 



Since World War II many new insecticides and repellents have 

 been found useful in the general field of applied entomology. Infor- 

 mation on their toxicity to animals has been obtained by the U. S. 

 Food and Drug Administration, the Public Health Service, the Army 

 Environmental Health Laboratory, the Department of Agriculture, 

 industrial pharmacological laboratories, and State experiment stations. 



Since many insecticides are used for controlling insects attacking 

 man as well as agricultural pests, much research has been designed 

 to appraise their hazards to man and animals when used for controlling 

 plant and livestock pests. The toxicity studies conducted by the 

 Army Environmental Health Laboratory, however, were designed 

 specifically to appraise the toxicity of repellents and insecticides for 

 use on man. The research was closely coordinated with the biological 

 studies conducted at the Orlando laboratory. The Public Health 

 Service has investigated the toxicity of some of the insecticides em- 

 ployed by State and Federal health agencies in connection with the 

 control of communicable diseases transmitted by insects. 



