Life-table experiments with Helisoma duryi (Wetherby) and Biomphalaria Pfeifferi (Krauss) at constant temperatures

Abstract

In an effort to find an ecological homologue that could be utilized as a biological control agent of the intermediate host species of economically important helminth parasites, age-specific life-table experiments with Helisoma duryi (Wetherby) ind Biomphalaria pfeifferi (Krauss) (intermediate host of Schistosoma mansoni) were carried out at a series of constant temperatures in a laboratory. The results showed that the lifespan and net reproduction rate of H. duryi were higher than those of B. pfeifferi over the whole range of temperatures investigated (18-35°C). The conclusion is reached that H. duryi should theoretically be capable of establishing viable populations in most of the habitats occupied by B. pfeifferi in South Africa.