Toxicity and adverse effects of macrocyclic lactones on dung beetles: A review

Abstract

The avermectins, milbemycins and spinosyns are part of macrocyclic lactones (ML) group, endectocides that are obtained by fermentation of different species of soil microorganisms. MLs are widely used in veterinary medicine and agriculture because of their potent activity against nematodes and arthropods. However, these compounds, when disposed in the faeces of animals, cause adverse effects on the edaphic fauna associated to dung. This review aims to document the adverse effects of avermectins and milbemycins on terrestrial invertebrates associated with dung, with emphasis on dung beetles from livestock environments under grazing systems. Information on the chemical structure and toxicological effects were compiled in laboratory and field studies of the compounds most used in domestic ruminants. This information is synthesized in 6 tables, which include the toxicological risk of avermectins (ivermectin, abamectin, doramectin and eprinomectin) and one milbemycin (moxidectin). The information compiled shows that the use of avermectins represents a high ecotoxic risk, especially for the immature stages of dung beetles. Moxidectin has been shown to generate less ecotoxic impact compared to avermectins, but research on this compound is still poor.