The Effect of Compensol on the Potency of Meta-Systox, 1988

Abstract

Abstract Compehsol is a mixture of 20 organic esters and was supplied by Bayer Australia Ltd. as an odour masking agent for Meta-Systox (i) 250 g/L EC. The masking agent was added at the rate of 25% v/v of the proprietary product. A population of Myzus persicae, which had been kept under insecticide-free conditions for several years, was used for all testing. Insects were exposed to a range of concentrations by spraying with a Potter tower producing a spray deposit of 1.6 mg/cm2. Solutions were sprayed directly onto test animals and the response assessed after a 24 h holding period on cabbage leaves. Log dose probability curves were calculated using probit regressions and were compared using relative potency and residual deviance. The following models were fitted: 1. single probit regression line for Meta-Systox (i) and Meta- Systox (i) plus compensol; 2. parallel probit regression lines for Meta-Systox (i) and Meta-Systox (i) puis compensol; 3. nonparallel probit regression lines for Meta-Systox (i) and Meta-Systox (i) plus compensol. The changes in deviance were calculated and compared to the relevant 5% value of X2.