The effects of cadmium, copper, lead, and zinc on the growth and reproduction of Proisotoma minuta Tullberg (Collembola).

Laboratory studies were conducted to evaluate Proisotoma minuta sensitivity toward selected heavy metals (Cd, Cu, Pb, and Zn). The experimental results showed a reduction in adult survival and no reproduction at the highest concentrations of Cd and Zn. Application of Pb at all levels resulted in large numbers of progeny and no significant mortality compared to controls. EC50 reproduction values for Cd, Cu, and Zn were 125, 696, and 283 microg g(-1), respectively. No significant difference in time from the introduction of adults into the test soils to the appearance of the first-instar animals was observed between different metal treatments. The growth rate of adults decreased for all metal treatments compared to the controls. It is suggested that the accumulation of metals in P. minuta affects metabolism and results in a slower growth rate. The absence of any statistically significant effect on mortality at all concentrations of Pb may be due to greater tolerance of P. minuta to Pb than to other metals.