Effects of Temperature on the Relative Toxicities of Cd, Cu, Pb, and Zn toFolsomia candida(Collembola)

EC50s for cadmium, copper, lead, and zinc were determined for juvenile production ofFolsomia candidaWillem, 1902, at 25, 20, and 15°C in a standard laboratory test system. Juvenile production ofF. candidawas too low at 25°C for reliable EC50-reproductionvalues to be determined. The EC50-reproductionvalues (μg g−1) for cadmium, copper, and zinc were similar at both 20 and 15°C (20°C: Cd, 590; Cu, 700; Zn, 900; 15°C: Cd, 540; Cu, 640; Zn, 590). Corresponding values for lead were considerably higher (20°C: Pb, 2790; 15°C: Pb, 1570). In aerially contaminated field sites adjacent to primary zinc smelters, zinc is invariably present in surface soils at concentrations of at least 50 times those of cadmium. The similarity of the EC50-reproductionvalues for cadmium and zinc inF. candidaat 20 and 15°C determined in this study strongly suggests that deleterious effects of mixtures of these metals on populations of Collembola in such sites can be attributed to zinc rather than cadmium.