Non-target effects of extended-release LongRange eprinomectin on coprophilous insects

I studied the effect of residues in dung voided by cattle treated with the novel parasiticide Extended-release LongRange (LR) on dung breeding insects. Field and lab studies over two years showed that residues are excreted for at least 25 weeks post-treatment at levels sufficient to reduce survival of some taxa with detectable effects on total insect abundance, taxa richness, and diversity. Using pitfall traps baited with dung with and without LR residues, I detected an effect of residues on attraction of some species of insects to dung. Results showed no changes in abundance, taxa richness, or diversity, but significant changes for individual taxa, albeit contrasting between years. Taken together, these findings show that cattle treated with LR in the spring will defecate residues at high enough concentrations to significantly affect the dung insect community for the entire duration of the grazing season