Whilst I'm still on holiday, today's guest blog comes from David Gibbons, RSPB's Head of Conservation Science. He will tell you about neonics and the impact they have on the domesticated honey bee and wild bumble bees.

An awkwardly-named group of insecticides – the neonicotinoids, or neonics, for short – has been in the news recently, with increasing evidence of their damaging impact on domesticated honey bees and wild bumble bees.

Chemical insecticides are commonly applied to crops by spraying, but this sometimes kills beneficial insects as well as pests. An alternative approach is to ‘dress’ crop seeds with an insecticide before planting. The insecticide becomes distributed systemically throughout the plant, killing only those insects that eat it. Or, at least, that’s the idea. Unfortunately, such systemic insecticides – of which the most widely used are neonics – end up in the pollen and nectar of crop flowers, and can be eaten by pollinators, such as bees. It has been known for a while that honey bees are killed by high concentrations of neonics. In a recent Italian study, for example, honey bees that flew through the dust cloud from the exhaust of a pneumatic seed drill during normal crop sowing operations received a large dose of neonics, and were all killed. What has remained less clear, however, was whether the concentrations that bees would routinely be exposed to in the field were harmful to them or not.

Two new studies have looked at the impact of neonics at field-realistic levels. The first, by researchers from Stirling University, exposed bumble bee colonies in the lab to realistic levels of the neonic imidacloprid, and then reintroduced them into the wild. Colonies treated with imidacloprid produced 85% fewer new queens than those that were not. In a separate French study, honey bees that were treated with realistic doses of a different neonic (thiamethoxam) were much less likely to return to their colony than those that were not; the bees became intoxicated by the neonic, lost their homing ability and died. Both studies suggested that numbers of bees would fall over time at the concentrations used in the experiments.

Bee populations are in decline for a variety of reasons, such as parasites and the loss of flower-rich habitats, but these new studies suggest that neonics may be playing more of a role in honey and bumble bee declines than previously thought.

So what is the RSPB doing about it? We are urging the UK Government to fund further research into the impact of neonics, particularly under field conditions. We are also assisting an IUCN Task Force to review all the available scientific evidence, and to devise an improved way of testing pesticides before they are approved for use. Perhaps, most importantly, we are supporting thousands of farmers in the work they are doing to help wildlife. Such actions are vital to safeguard populations of honey and other bees, and their roles as pollinators of crops and wild flowers.

What are your thoughts on this? It would be great to hear your views.

  • Martin seriously are these pesticides not banned in France ? Why an earth is RSPB not calling for the immediate ban of these chemicals; this is RSPB sitting on the fence, is it not ? There are real chances of utterly catastrophic declines in bee numbers; you are kicking the tin down the road. Act man !

    Can i also say that I am calling for an immediate 2metre field margin as compulsory for all farmers recieving CAP support payments from government. This would greatly help pollinators such as bees, wild flower species etc etc. This is no where near the 5% annual cuts that other government departments are having to implement and would help show, if only a little bit more clearly that the Conservative Party had any intention of standing by its phrase that "We are all in this together".

  • I really can't see why any scientist producing these chemicals should be surprised at the result! If the chemicals are systemic then they are bound to affect the pollen and nectar. So, not doubt spray drift/dust  lands on the wildlife margins around fields that farmers are paid to provide, and also affects butterflies etc nectaring on the wildflowers?

  • I do feel very strongly that there is nowhere near enough testing of pesticide chemicals before they are approved for use in the environment. They should be subject to the same degree of rigorous testing as drugs are for humans but tested to ensure that birds, animals and non target insects are not harmed by the pesticide in question. The chemical company should carry the full costs of this improved testing for the chemical in question. Time and again disasters have to be mitigated "after the horse has bolted". Take for example the vultures in India, poisoned by a pesticide chemical. The problem is that it is the conservation organisations who end up incuring the bulk of the costs for putting things right while the chemical companies incure little or no cost and move onto other things. The law in this country and world wide needs to be radically tighten up to prevent these repeated disasters , and the chemical companies made liable for environmental damage such as we see so often. However, as usual, I doubt whether Governments will respond to anything like the degree needed.