Abstract
Studies have been made on the mode of entry and the effect of hydrogen cyanide on the respiration of insects and have shown that cyanide caused complete respiratory inhibition in S. granarius but not in the other insects studied. The response of S. granarius to anoxic conditions differed from its reaction to cyanide, and insects paralyzed with cyanide were more resistant to methyl bromide than those which were active. Insects died when the amount of cyanide absorbed, calculated as a molar concentration of their total body water, was about the same as the concentration at which it combines with sugars to form cyanhydrins.