"Sumithion" is the tradename owned by Sumitomo Chemical Co., Ltd., Japan, and given to O, O-dimethyl O-(3-methyl-4-nitrophenyl) phos- phorothioate while its generic name registered at ISO and BSI is "feni- trothion." It is an organophosphorous insecticide having a broad range of insecti- cidal spectrum comparable to that of methyl parathion, and its toxicity to mammals and fish is low enough to make its handling of less concern. In 1959 the pesticide...