The effects of food quality on the life history parameters of the terrestrial isopod (Armadillidium vulgare (Latreille)).

Growth, reproduction, and survivorship of Armadillidium vulgare have been observed when laboratory populations were fed experimental diets consisting of leaves from different species of plant in different states of decay.Growth and fecundity were highest when the foods consisted of standing dead dicotyledonous plant leaves. Feeding on monocotyledonous material caused increased mortality as well as reducing both growth rates and reproductive output to very low levels. When the dicotyledonous material was extensively decayed before feeding, growth rates and survivorship decreased but this treatment did not significantly alter the results for monocotyledonous foods.Growth and survivorship rates were not significantly correlated with the total nitrogen content of the food but appeared to be related to the extent to which it could be digested and absorbed across the gut wall.Some of the implications of these results for the dynamics of field populations of terrestrial isopods are discussed.