#pesticide #neonictinoid #food #agriculture
Neonictinoids are a
group of pesticides that are chemically similar to nicotine. Their most uses
represent a risk to wild bees and honeybees, according to assessments published early
this year by EFSA. The Authority has updated its risk assessments of three
neonicotinoids - clothianidin, imidacloprid and thiamethoxam - that are currently subject
to restrictions in the EU because of the threat they pose to bees. There have
been many other studies relevant to neonictinoids hazards and risks towards
pollinators, but seldom consider the possibility that the risk of exposure may
change over time.
To fill the gap, in a fresh publication on the Proceedings of the Royal Society B, the co-authors conducted an experiment over 10 days and found out that bumblebee foragers continued to preferentially visit the thiamethoxam-laced feeders which indicates that workers can detect this pesticide and alter their behaviour to continue feeding on it. The increasing preference for consuming the neonicotinoid-treated food therefore increases the risk of exposure for the colony during prolonged pesticide exposure. Put it in short: Bumblebees acquire a taste for neonictinoids-laced food that can be compared to nicotine addiction in smokers, thus increasing risks.
Dr Richard Gill, from the Department of Life Sciences at Imperial College London and one of the co-authors, said and quoted by Guardian: "Given a choice, naive bees appear to avoid neonicotinoid-treated food. However, as individual bees increasingly experience the treated food they develop a preference for it." "Interestingly, neonicotinoids target nerve receptors in insects that are similar to receptors targeted by nicotine in mammals." "Our findings that bumblebees acquire a taste for neonicotinoids ticks certain symptoms of addictive behaviour, which is intriguing given the addictive properties of nicotine on humans, although more research is needed to determine this in bees."
Please refer to the original publication and the Guardian report for more details.
(Arce et.al. (2018) Foraging bumblebees acquire a preference for neonicotinoid-treated food with prolonged exposure. Proceedings of the Royal Society B (285) 1885. DOI: 10.1098/rspb.2018.0655)