Moult frequency of the isopod Porcellio scaber, as a measure of zinc-contaminated food

The effect of zinc‐contaminated leaf litter (250–10,000 μ/g dry wt.) diets on molting in Porcellio scaber, a terrestrial isopod was measured under controlled conditions. The duration of the premolt stage, the period between two successive ecdyses and the rate of molting, was followed during the exposure. Increased zinc concentration in the food caused prolongation of the molt cycle and decreased molt frequency. The duration of the premolt stage was not changed. Molt cycle was not affected drastically due to food deprivation. The application of molt cycle response to contaminated food in toxicity tests is discussed.