Neonicotinoid pesticide exposure impairs crop pollination services provided by bumblebees

• Published in: Nature (London) 2015-12, Vol.528 (7583), p.548-550
• Main Authors: Stanley, Dara A., Garratt, Michael P. D., Wickens, Jennifer B., Wickens, Victoria J., Potts, Simon G., Raine, Nigel E.
• Format: Article
• Language: English
• Subjects: 631/158/2456; 631/449/2668; 704/158/2458; 704/158/856; Analysis; Animals; Apples; Bees; Bees - drug effects; Bees - physiology; Behavior, Animal - drug effects; Behavior, Animal - physiology; Bumblebees; Crop yield; Crops; Crops, Agricultural - physiology; Economic importance; Ecosystems; Flowering plants; Foraging behavior; Fruit - physiology; Fruit trees; Global economy; Group Processes; Humanities and Social Sciences; Insecticides - adverse effects; letter; Malus - physiology; multidisciplinary; Neonicotinoid insecticides; Pesticides; Plant reproduction; Pollen; Pollen - physiology; Pollination; Pollination - drug effects; Pollinators; Reproduction; Science; Seeds; Seeds - physiology; Sublethal effects
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature16167

Despite substantial evidence that neonicotinoid pesticides can have negative effects on bees, there have been no reports that this leads to problems with pollination; here bumblebee colonies exposed to a neonicotinoid are shown to provide reduced pollination services to apple trees, leading to a reduction in seed number. Reduced pollination by neonicotinoid-exposed bees There is now substantial evidence that neonicotinoid pesticides can have negative effects on bees. However, it has not been shown that this leads to problems with the ecosystem service that bees provide, pollination. These authors show, in field tests involving 100 apple trees, that bumblebees exposed to a neonicotinoid provide less efficient pollination, leading to a reduction in seed number. Recent concern over global pollinator declines has led to considerable research on the effects of pesticides on bees 1 , 2 , 3 , 4 , 5 . Although pesticides are typically not encountered at lethal levels in the field, there is growing evidence indicating that exposure to field-realistic levels can have sublethal effects on bees, affecting their foraging behaviour 1 , 6 , 7 , homing ability 8 , 9 and reproductive success 2 , 5 . Bees are essential for the pollination of a wide variety of crops and the majority of wild flowering plants 10 , 11 , 12 , but until now research on pesticide effects has been limited to direct effects on bees themselves and not on the pollination services they provide. Here we show the first evidence to our knowledge that pesticide exposure can reduce the pollination services bumblebees deliver to apples, a crop of global economic importance. Bumblebee colonies exposed to a neonicotinoid pesticide provided lower visitation rates to apple trees and collected pollen less often. Most importantly, these pesticide-exposed colonies produced apples containing fewer seeds, demonstrating a reduced delivery of pollination services. Our results also indicate that reduced pollination service delivery is not due to pesticide-induced changes in individual bee behaviour, but most likely due to effects at the colony level. These findings show that pesticide exposure can impair the ability of bees to provide pollination services, with important implications for both the sustained delivery of stable crop yields and the functioning of natural ecosystems.