Tag Archives: pesticides

Perfect poisons for pollinators – available from your local garden centre

We try to make our garden welcoming for bees by growing flowers that provide pollen and nectar throughout the season. We also have some unkempt areas they might want to nest in and we don’t use any pesticides. I enjoy watching the bees foraging on the flowers as they come in to bloom and currently a large cotoneaster bush is full of small bumblebees buzzing loudly as they feed in the sunshine. It’s been very exciting this year to see bumblebees and solitary bees nesting in the dry-stone walls around the garden.

When we need new plants or compost, there is one local garden centre we use. It has a good range of healthy-looking plants and a very nice tearoom! In early spring, it’s also an excellent place to watch one of my favourite bees, the hairy-footed flower bee (Anthophora plumipes), whizzing about in the greenhouses full of flowers. Earlier this year, on a sunny Sunday afternoon in late March, I noticed that these Anthophora had set up nests in the old brick wall of one of the garden centre’s buildings.

Bee 4
A hairy-footed flower bee foraging on plants within the garden centre

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About a year ago, I saw a crowd funding request from the well-known bee-defender and researcher, Dave Goulson from the University of Sussex. He wanted the money to test whether plants sold in garden centres in the UK and labelled as “bee-friendly” actually contained bee-toxic pesticides, applied during production of the plants. I remember being quite shocked to read about this possibility – could I have been buying plants to help the bees that were in fact laced with bee-toxic chemicals?

I wanted to find out more so I got in touch with our favourite garden centre and asked whether they were using neonicotinoid insecticides on their plants. They reassured me that they were not. So far so good. I then asked if their suppliers used neonicotinoids in the compost on the plants they sold. The reply came back “I’m afraid I can’t answer that question without phoning every supplier. Also a few companies we deal with import some of their stock from other European countries. I’m happy to ask my local nurseries when I’m speaking to them.” That’s the last I heard.
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Dave Goulson got his money and went ahead with the analyses. The results of his tests have just been published and they don’t make happy reading;  here is a link to his blog on the topic. He and his colleagues bought 29 pots of flowering plants from well-known garden centres around Brighton (Wyevale, Aldi, B & Q, Homebase). Many were labelled “bee-friendly” and some had the Royal Horticultural Society endorsement “Perfect for Pollinators”.

They analysed a range of pesticides in leaves and pollen from the plants and found that most of the plants contained a cocktail of insecticides and fungicides. In the leaf analysis, only 2 of the 29 plants contained no pesticides. 76% contained one or more insecticide and 38 % contained two or more. 70% of the leaf samples analysed positive for neonicotinoid insecticides, well known for their toxic effects on bees. In the pollen analysis, neonicotinoids were found at levels known to cause harm to bees. So much for “Perfect for Pollinators”.

As a result of his work, B & Q announced that from February 2018 their plants would be neonicotinoid-free. Aldi revealed that they had stopped using neonicotinoids in October 2016, a few months after Goulson’s analyses took place. Neither B & Q nor Aldi  addressed the other chemicals found in the Sussex analysis.

The Horticultural Trades Association issued a statement that I believe is both silly and cynical, basically rubbishing Goulson’s analysis. You can read Dave Goulson’s rebuttal here.
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So, it really is true that when we buy plants to help bees in our gardens from garden centres, we may be unwittingly exposing the bees to harmful chemicals, despite the “bee-friendly” labels. Also, any insect that nips into a garden centre for a feed, especially early in the season when garden centres have an abundance of flowers, may be getting a hit of insecticide at the same time.

So, what do we do if we want to have a bee-friendly garden?

Dave Goulson recommends the following course of action: if you must buy plants, buy from an organic garden centre or, failing that, go to B & Q or Aldi. Better still, grow from seed or swap plants with friends and neighbours.
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One point that has not been discussed so far concerns potential effects on humans of these pesticides found in garden centre plants. Earlier this year, I bought some fruit bushes from the garden centre and these now have a nice crop of plump berries. If these plants have been treated with pesticides, and of course I don’t know if they have, then the fruit will presumably also contain these pesticides. This possibility makes me very angry. I grow fruit in our garden so that we can eat chemical free, fresh, good quality produce. I don’t want to ingest insecticides and fungicides with poorly defined toxic effects on humans.

The featured image shows a hairy-footed fower bee feeding from plants in a lane adjacent to the garden centre

Bumblebee tales and insecticide issues.

Here is an article I wrote for the February 2014 edition of the Marshwood Vale Magazine

Late December is a low time of year for wild life, so I was surprised to see several fat, stripy bumblebees out foraging in both Dorset and in Devon when the weather allowed. According to the textbooks they should have been hibernating but I was interested to learn that one of our native bumblebees, the buff-tailed, sometimes keeps colonies going during the winter. Winter-flowering plants like mahonia and heather provide the pollen and nectar they need.

Having unexpectedly seen these insects going about their business, I was all the more saddened to read a report from the US about the mass killing of bumblebees in an Oregon supermarket car park. During the summer, the lime trees in the car park were colonised by aphids and these dropped sticky material, honeydew, on to parked cars. To deal with this tiresome problem, some enterprising individual decided to kill the aphids by spraying the lime trees with insecticide. What they failed to notice was that the trees were in flower, making them very attractive to bumblebees. The result of this unfortunate set of circumstances was that as many as 50,000 bumblebees ended up dead on the tarmac, the largest ever recorded loss of bumblebees.

bumblebee on comfrey

The insecticide used to perpetrate this mass bee killing is one of a group of chemicals collectively known as neonicotinoids. These are relatively modern insecticides used very extensively in agriculture and in gardening for control of insect pests. For example, much of the oil seed rape grown in this country uses seed treated with these insecticides and many popular garden bug-killers are neonicotinoid-based. The neonicotinoids have the advantage that once applied to a crop, they are taken up systemically by the plant which then becomes poisonous to insects. There is concern that the poison will also be picked up by bees when they forage but the manufacturers say that the risk is low if the insecticides are used correctly. This includes not spraying crops when they are in flower and if bees are present.

Bees are very important for pollinating many of our crops and flowers. There had been worries for some time about a general decline in bee populations and although several contributory factors had been identified, including loss of habitat, pathogens and climate change, insecticides were also thought to be involved. Concerns about the effects of the neonicotinoids on bees intensified in 2012 when the results of field studies were released showing that at levels that did not directly kill bees, these insecticides impaired the survival of bee colonies and so could be contributing to the decline. These findings made the European Food Safety Authority take another look at the neonicotinoids and they came to the conclusion that safety testing on bees was incomplete for some of these chemicals. As a result, they recommended a two year moratorium on several agricultural uses of three of these insecticides. The prominent food retailer, Waitrose, took a wider view and asked all their suppliers of fruit, vegetables and flowers to phase out the three insecticides because of concerns about effects on bees, butterflies and other important pollinators.

Despite a groundswell of opinion against the insecticides in environmental groups, the UK government strongly opposed the ban on neonicotinoids, although it eventually had to follow the EU directive which came in to force in December 2013. The makers of the chemicals, Bayer and Syngenta, far from being contrite about the situation, have taken the European Commission to court over the decision and the National Farmers Union has backed the move. To be fair to the government, it has recognised that there is a problem for pollinators in the UK and is developing a National Pollinator Strategy to be implemented in 2014.

In the meantime there have been further indications of problems with these insecticides. Scientists in Japan had shown that the neonicotinoids might affect brain development in animals. Based on this and other work, the European Food Safety Authority decided that there was cause for concern and recommended that acceptable human exposure levels for some of these insecticides be reduced.

Studies in the Netherlands have shown that, following extensive use of the neonicotinoid insecticides in agriculture, they are contaminating ground water. The levels are high enough to kill invertebrates in ditches and in streams. Similarly, in Saskatchewan, prairie wetlands have been contaminated with the insecticides which may be killing midges and mosquitoes. The loss of these invertebrate species could have knock-on effects on birds that depend on them for food. The problem may be exacerbated by the persistence of the insecticides in soil. These are worrying observations and suggest that these chemicals are disturbing natural eco systems.

So, evidence is mounting that the neonicotinoids are endangering wildlife and particularly beneficial insects such as bees. Two opposing camps have emerged in this conservation battle. On one side is a wide range of environmental groups and campaign organisations who oppose the use of these insecticides. One the other side are the agrochemical companies and the farmers who want to see continued use.

What should we do? We should be aware of the effects of these chemicals on our environment and the effects they may have on pollinators. We should understand the arguments both in favour and against the use of these chemicals in agriculture. We should ask ourselves whether we really need to use these insecticides in our gardens especially if this results in the death of beneficial insects. Several prominent cities including Paris, Portland (Oregon), Seattle, Tokyo and Toronto have massively reduced pesticide use without any detrimental effects. Wouldn’t it be better if our gardens were insecticide-free and filled with bee-friendly flowers and bees?