The effects of trematode metacercariae (Brachylaemidae) on the slugsMilax sowerbiiFérussac andAgriolimax reticulatusMüller

Abstract

1. Infestation of the kidney ofM. sowerbiiandA. reticulatusby unencysted brachylaemid metacercariae led to a widespread necrosis of the organ. The necrotic debris was ingested into the gut crura of the parasites.2.M. sowerbiiis considered to be a natural intermediate host of the parasite andA. reticulatusto be an unnatural host, because inA. reticulatusparasitization led to a host mortality closely related to the degree of infestation, whereasM. sowerbiiwithstood the damaging effects of parasitization until the parasites reached maturity.3. InA. reticulatusthe rate of ingestion of food and the rate of egg production were reduced during parasitization.4. No further effects were observed in either host species.5. The possibilities and difficulties of using unencysted metacercariae to control pests are discussed.