#SkepticalTuesdays: “Neonics” and Bees | Vol. 2 / No. 39.2

Are neonictinoids killing bees? We're not honestly sure. Photo: Flickr user Umberto Salvagnin, CC BY 2.0
Are neonictinoids killing bees? We’re not honestly sure. Photo: Flickr user Umberto Salvagnin, CC BY 2.0

In this week’s SkepticalTuesday post, I’m talking about neonicotinoid pesticides, bees, and the 120-day exemption to the ban that’s just been granted to rapeseed farmers in the UK. 


So this weekend a friend of mine posted a link to this petition here. It’s in reference to the fact that, last week, the UK government passed an exemption to its current ban on the use of neonicotinoid pesticides in response to an application from the National Farmers’ Union. The petition’s pitch begins as follows:

Despite the fact that bee-killing pesticides are banned in the UK, the government just gave the go-ahead to farmers to plant these toxic-soaked seeds anyway. Any day now, Bayer and Syngenta’s toxic bee-killing seeds could be planted — wreaking even more havoc on our bees.” [emphasis theirs]

Now, aside from the fact that I’m a fan of good grammar and thus am very aware that it should read “toxin-soaked seeds,” I’m also a little put off by all the scaremongering around neonicotinoid pesticides, and a little frustrated by the single-minded denunciations present in the anti-neonicotinoid camp:

“Instead of listening to us, the government listened to corporations like Syngenta and Bayer — sidelining its own scientists who have warned how dangerous these chemicals are to bees and other pollinators.”

“This plan to plant UK fields with treated bee-killing seeds flies in the face of science and facts.”

“Companies like Bayer have been trying to overturn the neonics ban in the EU for years – using lawsuits and intimidation tactics to try and get their way. But we’ve been there at every step, fighting hard to make sure our precious pollinators aren’t stamped out by corporate greed.”[again, emphasis theirs]

The thing is — and I know you’re getting tired of reading me say this, but — it’s just not that simple. “Lawsuits,” “intimidation,” and “corporate greed” aren’t the reasons why the UK government has acted this way. But let’s back up and have a look at where things stand.

There are currently at least seven neonicotinoid pesticides on the market: acetamiprid, clothianidin, imidacloprid, nitenpyramnithiazine, thiacloprid and thiamethoxam. I believe the first of these was imidacloprid, and was developed by Bayer back in the early 1990s. They’re systemic pesticides, meaning you treat the plants with them and then anything subsequently eating the plants gets a dose (rather than treating the surface of the plants, or spraying the insects directly). They get their name from where they bind in the insect nervous system, receptors for the enzyme nicotinic acetylcholine, which is a pathway much more common in insects than mammals. So because they’re not terribly harmful to mammals and birds — certainly less harmful than many of the pesticides that came before them — they caught on pretty well.

And before you ask, no, Monsanto doesn’t make any neonics. Bayer, Takeda Chemical, Aventis, Novartis, and Syngenta are the big names I think.

Now the reason people have turned against neonicotinoids in recent years is because there’s a growing number of studies that suggest negative impacts on bee populations.

The impacts are not, by and large, catastrophic. If they had been, we wouldn’t be still using them more than twenty years on. Neonicotinoids are incredibly deadly when applied directly to bees. But, then again, so are boots. Terrible things do happen: farmers may not heed the warnings not to spray on flowering crops, for instance, and a couple of large bee kills have been reported in connection with neonicotinoid-laden dust clouds forming during sowing of improperly-treated seed. But primarily what is of real concern are what are called “sublethal effects.”

Bees, like the insects farmers are trying to eliminate, also get some of the chemical in their bodies when they feed off plants whose seeds have been treated with the pesticides. It’s a very small amount. Definitely not enough to kill them.

But that doesn’t mean it isn’t harming them.

The latest research suggests that even these “sublethal” amounts might be harmful to bee colonies, which are already facing a host of challenges: from parasites to fungal infections to viruses. Especially when bees seem to prefer the taste of pollen with neonicotinoids in it. But at present there is no “smoking gun” linking the chemicals to colony collapse disorder, especially when limited to the proper treatment of seeds (versus spraying). So what we’re talking about is the possibility that it’s contributing to a “death by a thousand cuts,” rather than being an immediate clear and present danger to the bees.

Which is part of the reason why I’m not that bothered by this latest story.

What the UK government has actually done, in response to a lot of lobbying from the farmers’ union, is allowed them to use treated rapeseed on 5% of the fields this season. It’s a 120-day license, and it’s in response to a problem the farmers don’t see any other way of solving: a major infestation of cabbage stem flea beetle. The union’s previous application was rejected because it was too broad, and the fact that they’re making a case for this based on an “emergency” suggests to me that they won’t be able to do it that often (under the hopefully sound logic that, if it’s an emergency, it doesn’t happen regularly). As far as I can see, it’s a very conservative move. It’s just not a 100% complete ban.

The farmers want more, the environmentalists want less. If a compromise is a solution in which neither side is completely happy, then I suppose I’m comfortable with that. In the meantime, if you’d like a really detailed review of the science surrounding neonicotinoids, you could do worse than going over Randy Oliver’s great posts over at scientificbeekeeping.com. His conclusion: there is no conclusion. Not yet, anyway.

But then, that’s what research is for.


Edit: A great bit of photo evidence from Twitterer @SekulicCCC:

"This is why we use #neonic seed treatments in Canola; untreated (left) vs treated (right). Flea beetle damage." Photo: Gregory Sekulic, CC BY 2.0
“This is why we use #neonic seed treatments in Canola; untreated (left) vs treated (right). Flea beetle damage.” Photo: Gregory Sekulic, CC BY 2.0


Richard Ford Burley is a doctoral candidate in English at Boston College, where he’s writing about remix culture and the processes that generate texts in the Middle Ages and on the internet. In his spare time he writes about science, skepticism, and feminism (and bees) here at This Week In Tomorrow.