[Combined and alternate control of Lymnaea truncatula Müller: comparative study of 3 technics for spreading of the molluscacide].

A combined control of Lymnaea truncatula with two applications of a 1-mg/l cupric chloride solution in April and the use of predatory snails in June eliminates the host snails in 77% of its sedimentary habitats in a single year. The better results were obtained with a first discharge of the toxic in the running water of the habitats, and with a further pulverization on emerged areas. A time of 6-12 h between the two applications increased the mortality rate for the L truncatula of winter generation. The increase of the toxic volume during the first application had little effect on the mortality increase.