Advances in vet and human medicines may have unintended consequences for the environment.
A few years ago a pest controller told me how lucky I was to live in one of the UK’s most rural counties (Powys). He added that, due to the prevalence of livestock farming, worm parasites were a problem for not only cattle, dogs and sheep. But also humans. If you’ve ever prepared wild meat or fish, you’ll realise how reliant we are on vet medicines to keep parasites at bay.
Much of our ability to do this is down to one of the Nobel Prize winner for medicine this year (2015). They discovered the compound avermectin. The active ingredient behind modern worming pesticide (or perhaps less ‘Silent Spring’, let’s call them medicines) and used extensively by livestock farmers today. (and for Covid-19 it seems)
The same week, during a walk on the hill, I noticed an excessive number of dead dung beetles lying around sheep and pony manure. Had the beetles – like wild bumblebees – suddenly been overcome by the number of mites attached to their body? Or had they ingested pesticide-heavy doses of dung?
Pour on pesticide
We take for granted that pesticides are ostensibly there to help us profitably produce affordable food. Whether via increasingly unfashionable though effective (soon to be banned?) neonicotinoids. Or the regular use of ivermectin to ensure efficiency in livestock production. Without too much thought on the impact of excessive applications may have on flora or fauna.
Sub-lethal is an expression used by scientists to say that something has an effect on something without killing it. Some of us drink coffee. But if we tank through 42 espressos, it could kill us. The same applies to still active pesticides excreted by livestock and consumed by dung beetles. Some of the beetles I saw on the hill, if not almost dead, looked decidedly wobbly.
Moon shine beetles
Two years ago the winner of the Ig Nobel prize – a light hearted engaging take of the Nobel Prize – studied ‘Dung beetle use of the Milky Way for orientation‘. Perhaps the next time we pop a pill for a headache or treat our pet and livestock for worms, we think about dung-dealing invertebrates not losing their way.
Addendum: another blog on insects here. Updated Oct 2021.