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Focus on the wild could avert plant pollination threat
28 September 2009
The global threat to the pollination of flowers and food production crops, highlighted by a dramatic decline in honeybee colonies, could be eased by a renewed focus on ‘wild' pollinators. Agri-environment schemes that encourage farmers to create bee-friendly habitats could be the key to increasing numbers of valuable wild pollinators like bumblebees in the wider countryside.
Dr Claire Carvell, a leading researcher with the UK Centre for Ecology & Hydrology (CEH) stresses the crucial role of wild pollinators: ‘The important point to note is that while the economic value of pollination, estimated at around £20 billion worldwide, is often credited entirely to honeybees, bumblebees and several other wild bee species are in fact much more effective pollinators of many crops such as field beans, clover, tomatoes and apples. This arises from a combination of morphological adaptations and their flower visiting behaviour.'
Wild pollinators are seen by Dr Carvell as a vital ‘insurance policy' to avoid the effect of honeybee losses such as those in the US, leaving crops like almonds and apples without their key pollinators, and in China where growers have been forced to pollinate apples by hand. ‘With honeybee numbers dwindling and the obvious risks of relying on a single domesticated species to provide almost a third of what we eat, it is vital to conduct more research into both managed and wild pollinator populations.'
Solutions to the decline in pollinators, apart from improvements to honey bee husbandry and breeding, include the commercial use of non-honeybee species for crop pollination and the conservation and restoration of high-quality habitats for all pollinators in the wider landscape. CEH research has been used to design options for bumblebees under the agri-environment schemes in England, which provide funding to farmers who deliver effective environmental management on their land. Dr Carvell explains: ‘We developed simple, low-cost seed mixtures containing pollen and nectar- rich forage plants. Our monitoring studies have shown that these can increase bumblebee numbers by more that 30-fold when sown at the edges of cropped fields. These targeted measures can also attract rare bumblebee species, many of which are now normally confined to the last remaining fragments of flower rich grasslands on protected areas and reserves. Our lab and field studies have shown that boosting forage resources significantly increases the number of reproductive bees produced.'
But the scale of take up of these options by farmers had been disappointing. ‘It is vital that we better engage farmers in this process', says Dr Carvell. ‘CEH are working with industry partners Syngenta who have set up a training scheme called Operation Bumblebee to spread the word on pollinator conservation. More than 1000 hectares of the pollen and nectar mix have been sown by over 500 farmers, and this approach is now being launched across Europe under Operation Pollinator (see website below).
Better news for the plight of honeybee colonies has emerged from research in Spain at Environmental Microbiology Reports. For the first time, scientists have isolated the parasite Nosema ceranae (Microsporidia) from professional apiaries suffering from honeybee colony depopulation syndrome. They report that they went on to treat the infection with complete success.