Good news and bad news
Neonicotinoids (neonics) have been in the news again, with for once some good news. These chemicals are harmful to the environment in many ways, for example polluting watercourses and killing aquatic insects (see below) but they are particularly dangerous for bees. Small amounts of neonics can poison thousands of them, causing problems with navigation and reproduction.
Although neonics were first banned for general use in agriculture 2017, year after year the Government has granted permission (a derogation) for them to be used to control insect pests of sugar beet crops. These authorisations were made despite expert advice and guidance against from such as the Health and Safety Executive and the Expert Committee on Pesticides. This year the Government finally said ‘no’ when the sugar beet industry made its routine annual request for exemption from the ban.
Joan Edwards, Director of Policy and Public Affairs at The Wildlife Trusts, said:
“For years, experts and more than 300,000 wildlife supporters have called for the ban against neonicotinoids to be upheld and The Wildlife Trusts are delighted with this decision. There is simply no place in modern sustainable agriculture for highly toxic pesticides that kill bees and poison soils and rivers. The focus must now be on a complete, sustainable transition away from a reliance on the use of neonicotinoids not just in agriculture, but also in pet flea treatments. This is a key source of chemical pollution in our waterways, with 10% of UK rivers found to contain toxic neonicotinoid chemicals.”
Neonics are a group of chemicals similar to nicotine developed as insecticides in the 1980s. They affect the nervous system and behaviour of insects and world-wide are extensively used to protect seeds and crops. One of them, imidacloprid, may be the most widespread insecticide in the world. Their use is a blunt instrument which harms non-target species, in this case especially bees. They exacerbate general insect declines and work against the Government’s legally-binding commitment to halt species losses by 2030.
The ban here for agricultural use perhaps only merits two cheers because, as Joan Edwards mentions, they continue to be used in pet treatment products for fleas and other parasites. Incredible as it may seem there are apparently more than 500 such products available in the UK which contain neonics, in particular imidacloprid and fipronil. Many of them are recommended for continual preventative treatment of the nation’s more than 20 million dogs, cats, and other mammal pets, rather than combating infestations when they occur. A single treatment for a large dog contains enough neonics to kill 25 million bees.
In research published by Imperial College in March 2023 Dr Andrew Prentis said: “So far, our use of parasiticides for pets has focused primarily on the animal and human health benefits, but even these are not well evidenced. Chemicals that have been banned in one sector are used indiscriminately in another with seemingly little consideration of the possible risks. This not only results in increased pollution of UK waterways but could also lead to parasite resistance due to overuse.”
The research shows that neonics are now present in waterways in urban areas in concentrations high enough to harm aquatic life, leading Imperial College to call for an urgent review of risk assessments and prescribing practices.
Not for the birds
Also calling for a re-evaluation of the risks of using neonics in pet treatments is a group of researchers who recently published their findings in relation not to insects, but to birds, in the journal Science of The Total Environment. They report that when they examined 103 blue and great tit nests (these being two species which use discarded fur to line their nests) they discovered that there were between two and eleven insecticides in each nest. All contained fipronil, and 89% contained imidacloprid and permethrin. These and other insecticides used in pet treatment were the most common.
They then looked at the birds’ breeding success, and this is where the concern arose. They say, “Overall, a higher number of either dead offspring or unhatched eggs was found in nests containing a higher number of insecticides, higher total concentration of insecticides, or a higher concentration of fipronil, imidacloprid or permethrin.” This indicates that exposure of the eggs to these “potent and persistent” chemicals adversely affects the birds’ reproductive success.
These findings lead to the suggestion that the environmental impact of veterinary drugs has been underestimated when compared to their agricultural counterparts. This evidence should give all pet owners pause for thought, especially those who think of themselves as supporters of nature conservation and environmental causes. It seems that neonics in these domestic products might have slipped under everybody’s radar
Perhaps the most chilling thing about neonics is the uncanny resemblance, in both impacts and widespread domestic and other uses, of DDT in the 1950s and 60s. In both cases the compromised reproductive success of birds provided early evidence of problems. It seems we never learn anything from past mistakes. Perhaps Rachel Carson’s landmark book, Silent Spring urgently needs a sequel.
The sting in the tail
The importance of being aware of the pollution which can be caused by some domestic products is emphasised by a recent Bumblebee Conservation Trust report setting out the results from BeeWalk, their national bumblebee monitoring scheme. Last year was the worst year for bumblebees since records began. Their numbers in Great Britain were nearly a quarter down on the average from 2010 to 2023. Poor and unsuitable weather for colony establishment in the spring and early summer was probably a major factor, especially for white-tailed (-60%) red-tailed (-74%) tree (-39%) southern cuckoo (-38%) garden (-12.5%) and buff-tailed (-9.5%).
Elimination of neonics in agriculture may have removed one source of pressure on bumblebee (and other insect groups’) numbers, but it is only one of many such constraints on sustaining healthy populations. Dr Richard Comont, of the Bumblebee Conservation Trust said: “The 2024 results from BeeWalk highlight just how vulnerable our bumblebee populations are to shifting climate and environmental conditions.”
We all have a part to play in helping to generate better news for our oppressed wildlife in the future.
References and links
Pollution of urban waterways: https://www.imperial.ac.uk/news/243875/toxic-flea-tick-treatments-polluting-uk/
Neonicotinoids and garden birds: https://tinyurl.com/e5s8ejat
Bumblebee Conservation Trust: bumblebeeconservation.org