The Influence of Lime on the Toxicity of Lead Arsenate to Cabbage Worms1

Abstract

Results of 2 yrs.'' expts. for the control of cabbage worms with various Pb arsenate treatments are presented. Data on the comparative effectiveness of dusts containing hydrated lime Loomkill Talc, Pyrax ABB and Bancroft Clay as diluents and Pb arsenate sprays with and without lime were obtained. All treaments containing lime showed markedly lower control efficiencies. Data on the arsenical residue loads of the various treatments are presented to show that the effect of lime on control is not accounted for by differences in arsenical load but to an actual reduction in the toxicity of the Pb arsenate. A brief discussion of the possible mechanism of this observation is included.