Evaluation of the Fungicide Manganese-Zinc Ethylene Bis(dithiocarbamate) (Mancozeb) for Sublethal and Acute Toxicity to Eisenia fetida (Oligochaeta)

This article describes the outcome of laboratory experiments to determine the acute and sublethal effects of the fungicide mancozeb on the earthworm Eisenia fetida. Apart from a standardized acute test, young worms, 25 days old, were exposed to mancozeb mixed into a urine-free cattle manure substrate. Five groups of 10 worms each were used per concentration level (0, 8, 44 mg/kg substrate). The following life-history parameters were measured: growth in consecutive weeks over a 6-week period, survival rate, maturation time, cocoon production, hatching success of cocoons, number of hatchlings per cocoon, and incubation time of cocoons over another 4 weeks. The results indicated that mancozeb had no significant detrimental effect on either growth or reproduction of E. fetida at the recommended dose (8 mg/kg) or at an estimated environmental concentration (44 mg/kg). The findings do not support the hypothesis that avoidance response to mancozeb could serve as an indication of toxicity.