The gastropod parasitic nematode Phasmarhabditis hermaphrodita does not affect non-target freshwater snails Lymnaea stagnalis, Bithynia tentaculata and Planorbarius corneus

Abstract

Phasmarhabditis hermaphrodita is a lethal parasite of several slug and snail species that has been formulated into a biological control agent. However, the complete host range of this nematode is poorly understood, in particular its potential to affect non-target aquatic snail species. Here we exposed three species of juvenile and adult freshwater snail (Lymnaea stagnalis, Planorbarius corneus and Bithynia tentaculata) to 30 and 150 P. hermaphrodita cm−2 and assessed survival, as well as differences in weight for 66 days. We show that P. hermaphrodita has no effect on the survival of L. stagnalis, P. corneus and B. tentaculata after 66 days of exposure. In summary, we found little evidence of P. hermaphrodita causing mortality to three freshwater snail species at two different life stages and believe that P. hermaphrodita would have little effect on non-target snail species in the wild.