Bees are responsible for the pollination of a few of the world’s most important crops, but have been experiencing significant population declines in recent years, Royal Holloway University reported.
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And now, publishing in the British Royal Society journal Proceedings B a team of French researchers is now saying their research is the “missing link” connecting their deaths and pesticides.
Bumblebees pollinating apple trees that become exposed to neonicotinoid pesticides demonstrate a decrease in their ability to pollinate the trees effectively. To that end, several studies have been conducted to look at what happens to bees when they are exposed to non-lethal amounts of different pesticides.
The researchers encouraged this last issue to be explored along with colony performance metrics using large colony monitoring datasets. They report also that the colonies exposed to the higher levels of the pesticide showed the strongest impairment.
More information: Dara A. Stanley et al.
“We found effects of neonicotinoid pesticide exposure on crop pollination services provided by bumblebees at the colony level”.
In essence, this means male bees are born during foraging periods, and this delayed drone production might “somehow disrupt this biological synchrony, and should therefore be addressed in terms of mating success or fitness value of reared drones”.
The debate over the use of neonics has centred on discrepancies between toxicity assessments in the laboratory, where bees are dosed artificially with insecticide, and the findings of field trials in the countryside. Bees are essential for the pollination of a wide variety of crops and the majority of wild flowering plants, but until now research on pesticide effects has been limited to direct effects on bees themselves and not on the pollination services they provide. Every year, over 75 million tonnes of apples are harvested globally, and insect pollination plays a major part in determining the size and shape of the fruit.
A common pesticide used on apple trees may make it harder for bumblebees to pollinate the trees properly and thus producing poorer quality fruit.
Known officially as colony collapse disorder (CCD), the great bee die-off has threatened the very existence of honeybees worldwide and one of the most important players in our ecosystem due to their pollination of numerous crops we grow for food.
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“The most exposed colonies modified the timing of their reproductive investment, delaying drone brood production in favour of increased worker brood production”, the researchers concluded.
