EFFECT OF THE DIET ON GROWTH AND REPRODUCTION OF EISENIA-ANDREI (OLIGOCHAETA, LUMBRICIDAE)

The effect of some vegetable bulking agents (straw, pine needles, pine bark, oak leaves and fern fronds) in mixtures with pig slurry (1 : 1 dry weight) on the growth and reproduction of Eisenia andrei, Bouche 1 972 was studied in cultures with either 1 or 8 individuals. Unlike ind ividual cultures, with no food limitation and no competition, the cult ures with 8 individuals represent a more real situation, with food com petition and mating processes. The maximum growth and reproduction rat es were achieved, both in the individual and in the group cultures, in the mixtures with straw and pine needles. The earthworms showed low g rowth rates and very low reproductive rates in the oak leaves and fern mixtures, both in cultures with one individual or 8 individuals. The high growth rates obtained here are in agreement with others in the li terature indicating the high potential of pig wastes for vermicomposti ng. Our results also confirm that there is a direct relationship betwe en E. andrei biomass and clitellum development so that the minimum wei ght for maturation is approximately 0.4 g. In addition, the remarkably high reproduction rate and cocoon production in the cultures with one individual suggests that mating is not an obligatory requirement for cocoon production.