Repellent Action of some Chemical Molluscicides on Schistosome Vector Snails

View More View Less
  • Department of Biological Sciences, University of Cincinnati


While it was shown that wheat germ cereal is able to attract some schistosome vector snails into a lethal concentration of some molluscicides (ICI 24223 and WL 8008), they tend to avoid it in the case of irritating chemicals (CuSO4, Na PCP, and Dinex). Demonstration of attraction in baited gradients of Bayluscide was difficult because snails were immobilized and killed at very low levels of the gradient. One amphibious strain of Australorbis glabratus was found less susceptible to all chemicals tested, because of its normal tendency to emerge from the water and remain out of contact with chemicals for the duration of these tests. Whether the rate of emergence is increased in these snails by the application of molluscicides is not certain, but such a reaction to the more irritating agents is not unlikely. The limiting effect of molluscicide-degrading bacteria on baited formulations of some molluscicides also is discussed.