ABSTRACT. – In the majority of digeneans infecting Insectivora, the larval stages are found in snails (cercaria) and terrestrial or aquatic invertebrates (metacercaria). The diets of both the Pyrenean desman Galemys pyrenaicus (Talpidae) and aquatic shrews (genus Neomys) include a wide variety of aquatic invertebrates that can act as the second intermediate host of several species of digeneans. In 2004, sampling was performed in the Py Natural Reserve (French Pyrenees). A total of 912 Bythinella rufescens (first intermediate host) and 167 non-mollusc aquatic invertebrates (second intermediate hosts) were studied for the detection of larval stages of digeneans. Two species of digenean trematodes were recovered as cercariae and metacercariae. These two species were Pseudocephalotrema pyrenaica (Lecithodendriidae) and Skrjabinophyetus neomydis (Nanophyetidae). In snails their general prevalence was 20.4% and 1.97% respectively. In the second intermediate hosts the corresponding prevalence rates were 22.15% and 3%, respectively. The study of larval digeneans of invertebrates can be used to detect the presence of small mammals.