Potential of two epigeic and two anecic earthworm species in vermicomposting of water hyacinth

The potential of two epigeic species (Eudrilus eugeniae Kinberg, and Perion yx excavatus Perrier) and two anecic species (Lampito mauritii Kinberg and Drawida willsi Michaelson) of earthworms was assessed in terms of efficienc y and sustainability of vermicomposting water hyacinth (Eichhornia crassipe s, Mart. Solm.). In different vermireactors, each run in duplicate with one of the four species of earthworms, and 75 g of 6:1 water hyacinth: cowdung as feed, vermicasts were produced with steadily increasing output in all t he reactors. E. eugeniae was by far the most efficient producer of vermicas ts, followed by the other epigeic P. excavatus. The two anecies came next, with D. willsi being the least effective which could generate only about ha lf the quantity of vermicasts achieved in a corresponding time by E. eugeni ae. In all the reactors, the earthworms grew well, increasing their weights by more than 250%. The maximum net gain of weight (average 30.7 g) was by E. eugeniae, followed by P. excavatus, L. mauritii and D. willsi. This tren d. which followed the efficiency of vermicast production, was also shown in terms of reproductive ability as measured by the number of offspring produ ced by the four species. (C) 2000 Elsevier Science Ltd. All rights reserved .