Studies of the behaviour of Artioposthia triangulata (Platyhelminthes; Tricladida), a predator of earthworms

A significant negative correlation between the numbers of earthworms and the flatworm was demonstrated in formalin-sampled lawns. Their distributions, recorded by a transect from a shrub border where the flatworm is suspected to have been introduced, indicated that predation may lead to earthworm extinction. Two different vermarium designs demonstrated a gradation of earthworm vulnerability to the flatworm due to depth within the soil and burrow width rather than preference for specific earthworm species. A strong correlation between the level of earth worm predation and flatworm movement implied active hunting. A predation rate was found to be 0.67 of an earthworm per flatworm per week with a metabolic conversion rate of 10%.