Following the publication last month of new research showing a link between the use of common neonicotinoid insecticides and bee mortality, the European Ombundsman, P. Nikiforos Diamandouros has launched an investigation into whether the European Commission has taken sufficient account of new scientific evidence on insecticide use, and appropriate measures to combat bee population declines.

The review was requested by the Austrian Ombundsman Board which stated that the Commission has not followed regulations which require a review of the authorisation of substances in the event that new scientific evidence suggests that they no longer meet approval criteria.

The continued use of neonicotinoid insecticides was permitted by the Commission in 2011, when it stated that it was aware of the toxicity of the substances, but argued that their use should be possible if exposure is limited to non-harmful levels. However, new research – including a study published in Science last month by a team at the University of Stirling, and summarised in an earlier Blog post – suggests that even very low levels of the substances have signficant detrimental effects on bee colonies.

More information about the inquiry is available on the European Ombundsman website.

The ongoing decline in wild bumblebee populations has caused worldwide concern, with evidence suggesting that the loss of critical pollination services could lead to a decrease in crop yields and the loss of many wildflower species. A number of reasons for the decline have been suggested and debated, but research from the University of Stirling, published in the journal Science last week, provides new evidence that pesticides used on flowering crops are having a significant effect.

The study, carried out by Dr Penelope Whitehorn and Steph O’Connor and supervised by Professor Dave Goulson at the University of Stirling, investigated the effects of neonicotinoid insecticides used as a seed dressing on flowering crops such as oilseed rape and sunflowers. These insecticides are systemic, travelling through the plant and occurring at low levels in nectar and pollen.

Findings reveal that bumblebee nests exposed to these low levels for just two weeks grew more slowly as a result, and showed an 85% reduction in the number of new queens they produced. Prof Goulson notes “Our work suggests that trace exposures of our wild bees to insecticides is having a major impact on their populations. Only queen bumblebees survive the winter to build new nests in the spring, so reducing the number produced by 85% means far fewer nests the following year. Repeated year on year, the long term cumulative effects are likely to be profound.”

Neonicotinoid insecticides are the best-selling insecticides worldwide and used broadly on a wide range of crops. As bumblebees often forage over a kilometre from their nest to find food, the study suggests that most nests in agricultural landscapes are likely to be exposed to these compounds. With insect pollination worth an estimated €22 billion a year to European agriculture, and many species of wildflower entirely dependent on bumblebees for pollination, Dr Whitehorn states “There is a clear need to re-evaluate the safety of these chemicals”.

This research is published as Whitehorn PR, O’Connor S, Wackers FL & Goulson D. Neonicotinoid pesticide reduces bumblebee colony growth and queen production and appears in the journal Science online and at the Science Express website.

New research presented at the American Chemical Society meeting in Washington this week (and reported in National Geographic) suggests that herbs and spices may offer an alternative to chemical pesticides. Oils from thyme, rosemary, mint and other herbs should repel or kill insect pests when sprayed onto crops.

Research indicates that the oils interfere with insects’ nervous systems and can also disrupt insects’ cellular membranes. Scientists think that insects may be less likely to develop resistance to plant-based compounds because they tend to be complex chemical mixtures.

However there are drawbacks to the potential widespread application of herbs and spices as pesticides. The compounds tend to evaporate quickly and degrade in sunlight; they must therefore be applied every few days, rather than every few weeks for conventional pesticides.

Other research presented at the same meeting indicates that plastics degrade far faster in water than previously thought. Scientists thought that plastics broke down only at very high temperatures and over hundreds of years. Now, new research by a team in Japan shows that polystyrene can degrade at temperatures of only 36 degrees celcius in the sea. As it degrades, the plastic is leaching toxic chemicals such as bisphenol A into the water. Bisphenol A has been shown to disrupt the reproductive systems of animals. The researchers suggest that plastic should be considered a new source of chemical pollution in the ocean.

Plant parasitic nematodes are a leading biotic cause of yield loss in crops, costing world agriculture an estimated US $125 billion annually. These small (0.25-3mm), unsegmented worms can affect crops in a variety of ways: altering normal root cell division, modifying plant cells for nutrient transfer, transmitting viruses and creating wounds that permit the entrance of other plant pathogens. Yet despite their enormous impact on important crop plants through-out the world, there are no effective, environmentally safe management strategies to treat or prevent plants from nematode infection. However, recent results from the EU-funded EcoTrain Project indicate that natural forms of control could provide a long-term solution to the problem.

Current nematode management strategies are largely dependent upon highly toxic pesticides (nematicides), which are harmful to the physical environment and reduce soil biodiversity by eliminating a variety non-target species.

By investigating the regulation of plant parasitic nematodes in the wild, scientists found that naturally occurring soil-dwelling predators could effectively control various nematode species.

The scientists took various micro-organisms, non-parasitic nematodes and microarthropods (such as mites) from the soil in a coastal dune grass (Ammophila arenaria) system, and examined the effect of different combinations on eight different species of parasitic nematode. Their results indicated that the most effective and sustainable method of biological control could be to treat crops with nematode suppressing soils, which contain a variety of soil-dwelling organisms found in wild plant populations. Their results also suggest that ‘conserving soil biodiversity is crucial in order to enhance the reliability of biological crop protection against soil-borne pests and diseases’.

These findings will undoubtedly be followed up with further investigations and more extensive field experiments. Especially in light of the European Parliaments approval of the Plant Protection Products regulation, which aims to phase out many chemical pesticides in Europe and promote of safer alternatives.

However, as parasitologist Tom Powers pointed out in 1992, the difficulty with this method of control appears to be the ability to transform it ‘into management system that can be manipulated by the growers’. After over 50 years of research, there are still no biological controls that are routinely used against plant parasitic nematodes.

Original Article: Piskiewicz, A.M., Duyts, H., van der Putten, W.H. (2008). Multiple species-specific controls of root-feeding nematodes in natural soils. Soil Biology and Biochemistry. 40: 2729-2735.

The EcoTrain Project is funded by the EU’s Research Training Network (RTN) Program.

Additional information:
Tom Powers (1992) Biological control of plant parasitic nematodes: Progress, problems and prospects: by G.R. Stirling, CAB International, 1991. Parasitology Today. 8: 320

European Parliament Plant Protection Products Regulations

The UK Government is ready to explore once more the use of GM technology in crops, hoping that this will offer a solution to the current world food crisis. Phil Woolas, the UK’s Environment Minister, has reportedly held private talks with the Agricultural Biotechnology Council, an umbrella group to promote the role of biotechnology in agriculture.

In an interview with the Independent newspaper yesterday, Mr Woolas said: “There is a growing question of whether GM crops can help the developing world out of the current food price crisis. It is a question that we as a nation need to ask ourselves.” Prime Minister Gordon Brown yesterday called on leaders at an EU summit to consider relaxing rules on the import of GM animal feed, as a way of lowering food costs for the poorest countries.

The only GM food crops currently available commercially are those which have been grown to be herbicide or insect resistant. There are very legitimate concerns that extensive growth of such crops will severely impact on the biodiversity of the countryside; as broad-spectrum herbicides such as Monsanto’s ‘Roundup’ indiscriminately affect wildlife. However, GM technology could offer benefits to developing countries if the focus was on research into higher yields, drought and disease resistance. Downing Street has commented that “GM crops are to be considered on a case-by-case basis, based solely on the science”.

Does GM offer a solution to hunger and poverty in the developing world as food prices rise and food shortages threaten?
The Science Policy Team invites you to comment on this article

A new study in the Journal of Environmental Health Management identifies new farming practices that could eliminate non-target effects of pesticides by 2010.

Fungal pests are a particular problem in the Netherlands due to climatic conditions. Pesticide usage in the Netherlands has declined since 1991, however current practices still result in spray-drift, that is the spreading of pesticides onto non-target plants, fungi and insects.

Using modeling techniques, the researchers were able to measure the impact spray drift had on non-target species in three different scenarios; the recent past (1999), the present (2005) and the near future (2010). The study showed that by introducing non-crop borders around agricultural fields, pesticide impacts on non-target species could be cut to zero. The paper has strong policy implications, given that current best practice techniques result in negative impacts on 41 per cent of areas next to treated fields, despite the use of low-drift nozzles and unsprayed borders.

A European policy framework directive for sustainable pesticide use is currently being developed as is a new Thematic Strategy on the Sustainable Use of Pesticides.

The BES welcomes comments from BES members and blog readers