
Reply To: Ivermectin
“A single injection of calves with ivermectin, at the recommended anthelmintic dose rate of 200 μg/kg of body weight, was effective in killing the larvae of the dung-breeding dipteran, Orthelia cornicina for up to 32 days post-treatment. Newly emerged beetles of the scarabaeine dung beetle, Copris hispanus, suffered 90 % mortality in dung dropped on days two and three after injection and 27.5 % mortality in dung of day 16. Feeding activity was greatly suppressed in dung of days 1–8, but was normal in dung of days 32 and 64, in which there was no substantial mortality. In the 1–16 day treatments, survivors showed aberrant reproductive development. When ovipositing C. hispanus were fed with day 3 dung, there was no adult mortality but oviposition rate was reduced and immature survival was zero. No mortality occurred among sexually mature adults of the dung beetle, Bubas bubalus when fed for five weeks on dung collected at intervals ranging from 1–32 days after injection. Substantial mortality was recorded among newly emerged beetles of Onitis belial, following exposure to ivermectin residues. Environmental implications of these results are discussed.”