The Effects of Field Applications of Some of the Newer Pesticides on Honey Bees1

Abstract

From these experiments residues of 0.25 lb. actual dieldrin per 100 gallons of spray may be highly toxic to honey bees (Apia MelliferaL.) for periods at least up to 96 hours after application. Sevin^® (1-naphthyl N-methylcarbamate) wet table powder, 50%, or a 36% mull at dosages of lib. actual per 100 gallons was highly toxic as a contact poison. Residues of 1 lb. actual Sevin were highly toxic for a period of 24 hours after application. Their toxicity diminished after a period of 96 hours. The toxicity of Am. Cyanamid No. 5223 (Cyprex®=dodecyl guanidine acetate) at a dosage of lib. per 100 gallons of water was not significantly different from that of the control bees.