Avoidance tests with Folsomia candida for the assessment of copper contamination in agricultural soils

The feasibility of assessing copper accumulation in agricultural soils using avoidance tests with a Canadian strain of Folsomia candida was investigated under laboratory conditions. The avoidance response to nominal copper sulfate concentrations of 0, 200, 800, 1600 and 3200 mg kg⁻¹ in OECD soil was inconsistent between trials with the standard plastic cup or a modified Petri dish method requiring less soil. However, combined results from three Petri dish trials decreased variability and provided a 75% avoidance level, close to the 80% criterion proposed for avoidance tests. A Copper avoidance EC_50s of 18 mg kg⁻¹was obtained using the Petri dish method whether tests were conducted with or without light. While Petri dish tests have potential as a cheap tool to distinguish metal contaminated soils from uncontaminated soils they would be unsuitable for tracking or quantifying changes in metal concentrations. throughout remediation. Advantages and limitations of the method have been presented.