Effects of the Fungicide Copper Oxychloride on the Growth and Reproduction of Eisenia fetida (Oligochaeta)

Abstract

The article describes a laboratory experiment to determine the effect of copper oxychloride on the earthworm Eisenia fetida. Copper oxychloride was used because it is the most commonly used fungicide in South African vineyards but not much is known about its toxicity to earthworms. In an experiment lasting 8 weeks, newly hatched earthworms of the species E. fetida were exposed to copper oxychloride mixed into a urine-free cattle manure substrate. Four groups of 10 worms were used per concentration level (control (4.02), 8.92, 15.92, 39.47, 108.72, 346.85 mg Cu kg substrate−1). The following life-history parameters were measured: earthworm growth in consecutive weeks, survival rate, maturation time, cocoon production, reproduction success, total number of hatchlings produced, and incubation time. Earthworm growth and cocoon production were significantly reduced at copper oxychloride exposure concentrations of 8.92 mg kg−1 and higher. Reproduction success in the 8.92 mg Cu kg substrate−1 was highest. From an exposure concentration of 15.92 mg Cu kg substrate−1 and higher, there was a considerable impact of copper oxychloride on reproduction. This could be seen from a reduced reproduction success, a reduced mean and maximum number of hatchlings per cocoon, and a longer incubation time, indicating a strong effect of low copper oxychloride concentrations on this earthworm species.