More evidence that ivermectin harms micro-scavengers

In parallel with mortality of vultures and other scavengers, critically important micro-scavengers like dung beetles are also being impacted by drug residues like ivermectin - used to treat elephantiasis, river blindness, and rosacea in people and liver flukes, eye worms, lungworms, roundworms, mites, horn flies and ticks in animals: PDF icon Verdu et al. (2015) Low doses of ivermectin impact dung beetles.pdf

Abstract: Ivermectin is a veterinary pharmaceutical generally used to control the ecto- and endoparasites of livestock, but its use has resulted in adverse effects on coprophilous insects, causing population decline and biodiversity loss. There is currently no information regarding the direct effects of ivermectin on dung beetle physiology and behaviour. Here, based on electroantennography and spontaneous muscle force tests, we show sub-lethal disorders caused by ivermectin in sensory and locomotor systems of Scarabaeus cicatricosus, a key dung beetle species in Mediterranean ecosystems. Our findings show that ivermectin decreases the olfactory and locomotor capacity of dung beetles, preventing them from performing basic biological activities. These effects are observed at concentrations lower than those usually measured in the dung of treated livestock. Taking into account that ivermectin acts on both glutamate-gated and GABA-gated chloride ion channels of nerve and muscle cells, we predict that ivermectin’s effects at the physiological level could influence many members of the dung pat community. The results indicate that the decline of dung beetle populations could be related to the harmful effects of chemical contamination in the dung.