Among the different insecticides tested for the armed forces, the most promising for use with pyrethrum proved to be piperonyl cyclohexenone. Because of its efficiency, safety, and the fact that it was activated by small amounts of pyrethrum, extensive studies were made on the insecticidal properties of compounds that were related to it, by Schroeder, Jones and Lindquist (1). The results were so encouraging that similar studies were made of a related compound.
The present paper reports observations were made upon another insecticide of this group known as piperonyl butoxide. It was found to be a safe and stable insecticide that kills many species of insects at reasonably low concentrations. When it was combined with small amounts of pyrethrins, the combination afforded a rapid knockdown, a greater mortality, and a long residual action. The stability of the combination was strikingly shown by the insecticidal properties of residues that are left from applications of surface sprays.
Contribution of the Entomological Development Laboratory, Dodge and Olcott, Inc., Baltimore, Md.
Read at a meeting of the American Society of Tropical Medicine, Miami Beach, Florida, November 6, 1946.