Date: August 16, 2016
Source: Centre for Ecology &
Hydrology
Exposure to neonicotinoid seed
treated oilseed rape crops has been linked to long-term population decline of
wild bee species across the English countryside, according to research
published in Nature Communications.
The research, led by the Centre
for Ecology & Hydrology using data provided by Fera Science Ltd and the
Bees, Wasps and Ants Recording Scheme, examined changes in the occurrence of 62
wild bee species with oilseed rape cropping patterns across England between
1994 and 2011 -- the time period spanning the introduction of wide-scale
commercial use of neonicotinoids.
The scientists found evidence
suggesting that neonicotinoid use is linked to large-scale and long-term
decline in wild bee species distributions and communities.
The decline was, on average,
three times stronger among species that regularly feed on the crop such as
Buff-tailed bumblebee (Bombus terrestris) compared to species that forage on a
range of floral resources, indicating that oilseed rape is a principle
mechanism of neonicotinoid exposure among wild bee communities.
Neonicotinoids are a group of
insecticide which can be applied to seed prior to planting. The active compound
is expressed systemically throughout the growing plant so can lead to potential
ingestion where pollinators feed on the pollen and nectar of treated crops.
These findings add to previous
small-scale and short-term exposure studies which have identified negative
effects of neonicotinoids on honeybees and a limited number of
commercially-bred wild bee species.
For five of the species
investigated, including the spined mason bee (Osmia spinulosa) and the furrow
bee (Lasioglossum fulvicorne), neonicotinoid use was equivalent to at least 20%
of local population extinctions of wild bees
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