Electric signals for separation of earthworms

The worm Eudrilus eugenioe is a species adapted to tropical climates and is highly demanded as fishing bait, therefore possessing high economic value. Separation of worms from humus is typically performed by manual, mechanical, behavioral and electric methods. The objective of this study was to characterize electric pulses for separation of worms (Eudrilus eugenioe) from humus. To determine separation efficiency of worms from humus, a controlled pulse generator was used with frequencies of 1 and 5 Hz, voltages of 100 and 200 V, peak widths of 2, 3 and 4 x [10.sup. -3] s and exposure times of 15 and 30 min. The electrical pulse characteristics which resulted in greatest separation efficiency were: 1 Hz, 2 x [10.sup. -3] s and 200 V; and the maximum displacement index was 80% which occurred under these conditions. The survival index was 100% for the pulses which resulted in the greatest separation indices. Key words: vermiculture, vermicomposting, electric stimulation A minhoca (Eudrilus eugenioe) e uma especie adaptada ao clima tropical, razao pela qual e bastante demandada como isca para pesca e tem grande valor economico na atualidade. Normalmente, a separacao de minhocas do humus e realizada por metodo manual, mecanico, comportamental e eletrico. O objetivo desta pesquisa foi, caracterizar pulsos eletricos na separacao de minhocas (Eudrilus eugeniae) do humus. Para determinar a eficiencia de separacao de minhocas do humus foram utilizados um gerador de pulsos controlados com: frequencia de 1 e 5 Hz, tensoes de 100 e 200 volts, duracao do patamar de 2, 3 e 4 x [10.sup. -3] s e tempo de exposicao de 15 e 30 min. As caracteristicas eletricas dos pulsos, que resultaram na maior eficiencia de separacao, foram: 1 Hz, 2 x [10.sup. -3] s e 200 V. O indice de deslocamento maximo foi de 80%, ocorrendo na frequencia de 1 Hz, com patamar de pulso de 2 x [10.sup. -3] s e tensao de 200 V. O indice de sobrevivencia foi de 100% para os pulsos que resultaram em melhores indices de separacao. Palavras-chave: vermicultura, vermicompostagem, estimulacao eletrica