David's blog posts tagged with 'garden'

“Bee Informed” – but not by this propaganda

Apr

26

 

Pop in to your local Homebase, find the long aisles where the plethora of garden pesticides are arrayed, and you will now find glossy leaflets prominently displayed with a picture of a bumblebee on the front, entitles “BEE INFORMED - WHEN USING INSECTICIDES IN YOUR GARDEN”. So far so good, I can’t really argue with that. But read on.

Inside the leaflet, you will learn that bees are important. Excellent stuff. Then you will be told that bee health has been compromised, and that “A number of culprits have been identified, including:

• Parasitic mites such as Varroa

• Bacterial, fungal and viral diseases

• Habitat loss and degradation

• Genetic factors”

All true, but you might be thinking that there is an obvious omission from this list. Read on, and you will learn that “Some claims have also been made of a possible link between the decline in bee populations and the use of some insecticides. This has not been shown scientifically”. Hmmm.

The “some insecticides” they refer to are presumably neonicotinoids, the controversial chemicals that have been at the heart of a ferocious debate for ten years or more. Neonicotinoids are the active ingredient in many garden insecticides, and you may well also drip them on the neck of your dog or cat to prevent fleas. A group of scientists at the European Food Standards Agency spent six months examining the safety of these chemicals, and concluded that they pose an “unacceptable risk”. As a result, a majority of European countries voted for a ban on several of the most widely used neonics on flowering crops that bees might visit (the UK government opposed, of course). Since then, a huge review of over 1,000 scientific papers was written by 28 scientists from all over the world (I was one), under the auspices of the International Union for the Conservation of Nature, and it concludes that neonics are harmful to bees and pose a serious threat to biodiversity. On top of that, The European Academy of Sciences published a huge report on the subject last year, written by a team comprising a leading scientist from every European state. Their findings echoed the earlier reviews; these chemicals are damaging to bees and other wild insects. None of this is particularly surprising; these are highly poisonous neurotoxins that kill insects of any sort in minute, near-infinitesimal doses. They are also highly persistent, sometimes lasting for years in soil and plants.       

So who produced this wildly misleading leaflet? The Crop Protection Association, the Horticultural Trades Association, and the British Beekeepers Association (BBKA). The first two come as no surprise; these are essentially wings of the agrochemical industry, pushing their poisons as usual. But the BBKA? Really? Shame on you.

The leaflet goes on to say that “Provided that garden care products are used as directed on the label, they will not pose a problem to bee health.” Yet a recent Swedish study, published in the most prestigious scientific journal in the world (Nature), showed huge impacts of neonics on bumblebees and solitary bees when the chemicals were used by farmers ‘as directed on the label’. Remember that, 50 years ago, the agrochemical industry assured us the DDT was safe, until it turned out that it wasn’t. Later, they told us that organophosphates were fine, except they weren’t. Do you believe them this time? I don’t. 

The simple truth is that none of the array of chemicals on sale in your local garden centre are necessary. I have a two acre garden that I manage singlehandedly, while having a full-time job, and I manage to grow heaps of flowers and veg. It isn’t the tidiest garden ever, but it looks wonderful (to me anyway!). Every year my broad beans are attacked by a horde of black bean aphids, but after a week or two an army of ladybirds, hoverflies, lacewings and tiny parasitoid wasps come to the rescue, and in no time they are gone. The bean plants look a bit dog-eared, but they recover and give a great harvest. No need for insecticides. I’m ashamed to admit I used to use glyphosate, and I still have an old pot of it in the shed still, but since the World Health Organisation announced that it is highly likely to be carcinogenic[1] I have stopped using it. Hoeing works just fine, and I have kids and pets in the garden.   

To be honest, I expect nothing else from the pesticide industry. They are a hugely powerful and rich lobby that spends a fortune trying to convince us that we need their products. But why does Homebase push their propaganda? I guess money is the answer. Why does the BBKA support it? Do their members agree? I’m pretty sure that most of them don’t. The senior management of BBKA have always had an oddly cosy relationship with the agrochemical industry, to the horror on many of the BBKA members who I have spoken to. I guess that money has changed hands at some point.

The leaflet also mentions the Royal Horticultural Society as a source of further information, though it is not clear if RHS endorse it. I sincerely hope not.

We should boycott Homebase until they stop displaying this leaflet (my boycott started today, but on my own I don’t think that will bring them to their knees). We should campaign for these chemicals to be withdrawn entirely from garden use. I would love to see ALL pesticides banned for use in the garden; there is just no need, no need at all.  

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The leaflet can be downloaded from the Crop Protection Association directly here:

http://www.cropprotection.org.uk/media/31346/bee_safe_leaflet_v13_final_final_jan_12.pdf 



[1] Glyphosate, a herbicide, is the most widely used pesticide in the world. It is in most foods we eat. Recent studies have found significant levels of glyphosate in urine of almost every German of 2,000 tested, with the highest levels in children.  

Pesticides in “Bee-Friendly” flowers

Jun

01

Take a walk around your local garden centre and you will see a mouth-watering display of gorgeous plants on display. You might note that some are specifically labelled as bee or pollinator friendly, with a picture of a cartoon bumblebee on the label. The Royal Horticultural Society (RHS) provide a “Perfect for Pollinators” logo which can be added to the label of any of the long list of garden plants that they judge to be good for pollinators. If you like hearing the buzz of bees in your garden, and want to do your bit to help our wildlife, you might well be tempted. Indeed, I have often spent a small fortune myself on potted plants when I only went to the garden centre to buy a pack of vegetable seeds. The big DIY and supermarket chains are similar – somewhere by the main entrance you will see a range of colourful plants in plastic pots and trays, some of them labelled as bee-friendly.

            If, like me, you’ve ever succumbed to the temptation to buy these plants, you may be somewhat concerned by the results of our latest research. Here at Sussex University we have been busy screening the leaves, pollen and nectar of these plants to see if they contain pesticides. We bought flowering plants from a range of major outlets; Wyevale (the biggest garden centre chain in the UK) and also Aldi, B&Q and Homebase. We deliberately bought plants that are known to be attractive to bees and butterflies; most of them had a bee-friendly logo, often the RHS one.

We found that most of these plants contained a cocktail of pesticides, usually a mixture of fungicides and insecticides. I wish I could say that I was surprised by the results, but sadly I wasn’t, for this mirrors similar studies performed in other countries. Only two out of 29 plants contained no pesticides. Seventy six percent of them (22/29) contained at least one insecticide, and 38% contained two or more insecticides. One flowering heather plant contained five different insecticides and five different fungicides – a veritable toxic bouquet. Seventy percent of the plants contained neonicotinoids (insecticides that are notorious for their harmful effects on bees), commonly including the ones banned for use on flowering crops by the EU (for the technically minded, 38% contained imidacloprid, 14% contained thiamethoxam and one contained clothianidin). Enough detail; you get the picture. Plants sold as ‘bee-friendly’ plants are usually stuffed full of pesticides.

Just before our results went public, B&Q (who knew that out study was appearing imminently) announced that they were prohibiting their suppliers from using neonicotinoids on their plants from February 2018. This is of course a great step forwards; well done B&Q, next time I need some screws or shelving I will be heading your way, and I hope others do likewise. Once our results were out Aldi declared that they stopped using neonicotinoids in October 2016 (we bought the plants we tested from them in July 2016). Also great news.  

Homebase and Wyevale have so far declined to make any public comment, despite high profile articles about the work in the Daily Mail and Independent. The Horticultural Trades Association, which represents the gardening industry, has been less than positive (http://bit.ly/2rXM4sL). Firstly, they claim that the three neonicotinoids banned by the EU on flowering crops are not used in horticulture (which would seem to simply be untrue). They then go on to say the “industry works closely with government bodies and other stakeholders to uphold high standards of environmental management”. They say that the concentrations of pesticides we found are at “low levels”, that we only sampled from “a very restricted area of the country”, and they suggest that the presence of clothianidin in one plant shows that our samples were contaminated, since this product has never been approved for use on ornamentals. In other words, instead of engaging positively, they try to undermine and play down our work.

Let’s have a closer look at their criticisms. Firstly, the concentration of the pesticide is of course important. Modern analytical techniques are very sensitive and tiny concentrations can be detected. Perhaps the concentrations we detected are all too low to do any actual harm? For neonicotinoids, the concentrations typically found in the nectar and pollen of treated crops such as oilseed rape are in the range 1-10 parts per billion (ppb). Exposure to such concentrations has been found to impair bee navigation and learning, reduce egg laying, lower sperm viability, and suppress the immune system. In a study with bumblebee nests we found that giving them pollen with 6ppb of neonicotinoid reduced nest growth and resulted in an 85% drop in the number of new queens produced[1]. In the ornamental flowers, we found imidacloprid at up to a maximum concentration of 29ppb, clothianidin at 13ppb and thiamethoxam at 119ppb. In other words, concentrations far higher than those known to harm bees. The claim that we only sampled from a “very restricted area” is pretty absurd. It is true, we sampled from stores near Brighton, but these are huge chains with a national/international supply network. Are HTA really suggesting the problem is peculiar to East Sussex? On the presence of clothianidin and the suggestion that our samples were contaminated, HTA need to learn a bit more about pesticides. As well as being used as a pesticide in its own right, clothianidin is a breakdown product of the closely related chemical thiamethoxam. The Ageratum plant containing the clothianidin also contained much higher levels of thiamethoxam, presumably the product with which it had been treated. So, not evidence of contamination at all.          

            I would argue that, by quibbling over details and focussing on neonicotinoids, HTA are missing the bigger picture, as indeed are B&Q and Aldi. Neonicotinoids are undoubtedly bad for bees, but what about all the other chemicals? If I buy a plant to feed to bees I don’t want it to have been drenched with a pyrethroid or organophosphate insecticide either. Both are highly poisonous to bees (and organophosphates are exceedingly toxic to people too). Even some of the fungicides have been found to harm bees[2]. If I’m buying plants to encourage wildlife, I don’t want the lingering worry that I might be accidentally poisoning my bees, hoverflies and butterflies. I don’t use any pesticides in my garden – I simply don’t need them. I don’t want to bring them in accidentally.   

            It is a shame that the horticulture industry seems largely unwilling to engage over this issue. It is perhaps not surprising, since their track record is not great. They’ve been continuing to promote and use peat-based composts for many decades despite the ready availability of perfectly good alternatives (in case you didn’t know, peat extraction does terrible damage to peat bogs, exacerbates flooding and ultimately releases huge amounts of carbon dioxide into the atmosphere). With birds, bees and butterflies all in rapid decline (2016 was the worst year ever for British butterflies), we all need to be willing to admit our mistakes and change our ways. HTA and the big garden chains such as Wyevale could really help to make a difference if they wanted to. I’d be very happy to help if they would like some advice (Wyevale, how about launching a new organic range of genuinely bee-friendly plants?)

Until the gardening industry gets its act together, I’d suggest the following. If you must buy plants, buy from an organic nursery, or failing that from B&Q or Aldi. Better still grow them from seeds, or if you haven’t the patience, plant swap with your friends and neighbours (if anyone wants some comfrey roots and lives near E Sussex I’d be happy to give you some, pesticide free, it is a fabulous plant for bees). We really can make our gardens into havens for wildlife, but not by driving to the garden centre to buy pesticide-laced plants grown in peat-based compost inside disposable plastic pots.    

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Our research describing in detail the pesticides we found is here: http://www.sciencedirect.com/science/article/pii/S0269749117305158 

It was published in the journal Environmental Pollution, May 2017. 



[1] Whitehorn et al. 2012, Science, 336: 351-352.

[2] Bernauer et al. 2015, Insects 6: 478-488