Discachaeta arcipes (Pand.) and Parasarcophaga cmdeni Rohd were isolated from the mollusc Helicella candicans. A conclusion is made that D. arcipes is an obligate parasite and P. emdeni is a necrophage of the molluscs. Data are presented on ecology and distribution of the mentioned species. The stomatopharynx apparatus and posterior part of the D. arcines larva (stage III) and the P. emdeni female are described and pictured.