Studies on Toxicity to Honeybees of Acid Lead Arsenate, Calcium Arsenate, Phenothiazine, and Cryolite1

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Abstract
Various insecticides that are used for the control of the codling moth have been used in toxicity tests against the honeybee, in the hope of F1nding one that is harmless to bees. Weighed amts. of acid Pb arsenate, Ca arsenate, phenothiazine, and cryolite were F1nely suspended in measured volumes of 60-65% sucrose sirup, and measured volumes of these suspensions were then fed to bees individually in a single dose by the capillary pipette method. After being fed, the bees were confined in cages, given an adequate supply of sugar sirup, and placed in an incubator at 83-85[degree] F for 3 days, the number dead at the expiration of that time being used as a measure of toxicity. The medium lethal doses of the arsenicals and of cryolite, in [gamma] of active ingredient per bee, were as follows: Ca arsenate (As), F1ne and medium 0.7, commercial 0.6, coarse 1.3; acid Pb arsenate (As), F1ne 5, commercial 13, coarse 185; synthetic cryolite (F), F1ne 42, medium 5.5, coarse 13. Phenothiazine was scarcely toxic at all, even in doses up to 570 [gamma] per bee.