The Toxicity of Zinc to Terrestrial Isopods in a "Standard" Laboratory Test

A method is described for assessing the effects of metals on the food consumption rate of isopods from measurements of fecal production. The effects of zinc in the diets of two isopod species, Porcellio scaber and Oniscus asellus, were tested. The metal was fed to the isopods on leaves of field maple (Acer campestre) contaminated with concentrations ranging between 1000 and 10,000 μg Zn g−1 leaf dry wt. Significant reductions in feeding rates were observed of the highest concentrations of zinc. The test employed in this study is quick, cheap, and relevant for estimating sublethal effects of metals on isopods.