Shade as a means of ecological control of <i>Biomphalaria pfeifferi</i>

Abstract

Species of Biomphalaria are attracted to light and negatively affected by darkness. Artificial shading of a breeding-site eliminated a population of B. pfeifferi within six weeks. The site was recolonized by eight weeks after the shade was removed. The time taken for recolonization suggests that shade acts not only by affecting snail behaviour but also indirectly by removing the diatoms which are food for the snails. The use of natural shade for ecological control of some snail vectors of schistosomiasis deserves, at least, careful consideration.