Survival and growth of Aporrectodea longa (Lumbricidae) fed on sheep and cow dung with and without moxidectin residues

Abstract

Deep-burrowing (anecic) earthworm species that can enhance the incorporation of surface organic matter such as dung are rare in pastures in southern, mainland Australia. The anecic earthworm Aporrectodea longa (Ude) (Lumbricidae), which is common in northern Tasmania, has the potential to colonise pastures in the higher rainfall areas of south-eastern Australia and is being considered for introduction there to improve soil properties and pasture production. However, in these areas, antiparasitic drugs are widely used in grazing ruminants and residues of these drugs are excreted in the faeces. We studied the effects of the broad-spectrum anthelmintic moxidectin in sheep and cow dung, on the survival and growth of A. longa in the laboratory. Over a 10-week period, there were no lethal or sublethal effects of the drug and its metabolites in sheep and cow dung on A. longa. The worms removed more sheep dung than cow dung from the soil surface and hence had a higher growth rate on sheep dung.