So a much needed update on the recent news involving bee harming pesticides….here in the UK at least, the toxicology studies on the pesticides in the past have not been only funded by but also conducted by the pesticide companies themselves, such as Bayer and Synenta. It is a case of foxes guarding the hen house, and not difficult to see how scientific objectivity could be being skewed here, pesticides being a multi-billion pound industry to these companies…they want farmers to buy and use pesticides and they consistently speak out against research showing they could pose a risk to bees, pollinators and other invertebrates (their studies have also been shown to have a number of major limitations by independent scientists, being very poor at examining sub-lethal effects, long term effects or cocktail effects of pesticide combinations). Neonicotinoids are amazingly effective insecticides..they just aren’t selective and take down both pest and beneficial species.
Quoting Prof. Dave Goulson from a New Scientist article:
“Neonicotinoids are widely applied as a seed dressing to crops such as oilseed rape, and being systemic they spread through the plant into the nectar and pollen. They are highly toxic to insects: for example the “LD50” – the dose that kills half of test subjects – in honeybees is about 4 billionths of a gram.
To put that in context, 1 gram – little more than the weight of a sachet of salt – would provide an LD50 to 250 million honeybees, or roughly 25 metric tonnes of bee. They are neurotoxins, binding to neural receptors in the brain and causing swift paralysis and death.”
https://www.newscientist.com/article/dn23465-bees-need-europes-pesticide-ban-whatever-the-uk-says/ Yes this issue is a valid one Jane…here in the UK at least, the toxicology studies on the pesticides in the past have not been only funded by but also conducted by the pesticide companies themselves, such as Bayer and Synenta. It is a case of foxes guarding the hen house, and not difficult to see how scientific objectivity could be being skewed here, pesticides being a multi-billion pound industry to these companies…they want farmers to buy and use pesticides and they consistently speak out against research showing they could pose a risk to bees, pollinators and other invertebrates (their studies have also been shown to have a number of major limitations by independent scientists, being very poor at examining sub-lethal effects, long term effects or cocktail effects of pesticide combinations). Neonicotinoids are amazingly effective insecticides..they just aren’t selective and take down both pest and beneficial species.
Quoting Prof. Dave Goulson from a New Scientist article:
“Neonicotinoids are widely applied as a seed dressing to crops such as oilseed rape, and being systemic they spread through the plant into the nectar and pollen. They are highly toxic to insects: for example the “LD50” – the dose that kills half of test subjects – in honeybees is about 4 billionths of a gram.
To put that in context, 1 gram – little more than the weight of a sachet of salt – would provide an LD50 to 250 million honeybees, or roughly 25 metric tonnes of bee. They are neurotoxins, binding to neural receptors in the brain and causing swift paralysis and death.”
https://www.newscientist.com/article/dn23465-bees-need-europes-pesticide-ban-whatever-the-uk-says/
…with such amazing lethal toxicity to insects, it isn’t hard to see why they could be harmful to insect populations, especially as they can be cumulative, binding to receptors and building up in an insect’s system over time. Out of direct sunlight (and UV exposure), they can also be persistent in the environment, lasting multiple years. Here in the UK, research has found neonics appearing in wildflowers near crop fields (despite them being used systemically, which should avoid this collateral fallout, in principle at least.) Over 80% of the rivers in the UK have recently been found contain varying levels of neonics, and we have no idea what impact this will be having on riverine invertebrate communities, and they have also been linked to bird declines here.
My own view is that habitat loss is certainly very important (particularly for bees and pollinators), but the effect of neonics on insects and invertebrates I think has largely been overlooked or downplayed, and that they may be having an important impact on insect declines as an aside to habitat loss.
Sam Gandy
