[Effects of 2 metal salts (FeCl3, CuCl2) on predatory activity and egg laying of Zonitoides nitidus Müller (Mollusca, Gastropoda, Pulmonata)].

Laboratory observations were made on the effects of two metal salts, FeCl3 and CuCl2, on the life of a terrestrial predatory snail, Zonitoides nitidus. These effects were studied, either by direct dipping of predators in the salts with the study of their predation on living lymnaeid snails during the 10 days after dipping, or by exposure of intoxicated, living snails to predators during 28 days. The number of eaten preys and the number of egg laids steadily decreased in the Z. nitidus groups dipped in the toxics during more and more long times. The same results were observed in the Z. nitidus groups eating intoxicated preys after day 7 of experiment. More toxic effects were obtained in all the egg laids of predators in contact with CuCl2 than with FeCl3. The significance of these results is discussed in relation with the joint and alternate control of L. truncatula by chemical and biological means.