A new report in Proceedings of the National Academy of Sciences, states bees are having to start foraging earlier than the typical two to three-weeks-old, as older workers are being killed off by disease, lack of food, parasitic attacks, pesticides and other factors.
Using tiny radio tracking devices on thousands of bees, scientists have found that these early-starters completed fewer foraging flights on average, and were more likely to die on their first sortie as they had not gained vital experience in the safety of the nest.
The scientists used data from the bee tracking to model the impact on honey bee colonies in a computer simulation – finding that stress leading to chronic forager death among older bees led to a change of behaviour within the hive – with an increasingly younger foraging force becoming the standard, which in turn led to poorer performance and more rapid deaths – dramatically accelerating colony decline.
Lead researcher Dr Clint Perry, from the School of Biological and Chemical Sciences at Queen Mary, University of London, stated: ‘If [this] increased death rate continues for too long, or the hive isn’t big enough to withstand it in the short term, this natural response could upset the societal balance of the colony and have catastrophic consequences.’
He added: ‘Our results suggest that tracking when bees begin to forage may be a good indicator of the overall health of the hive. Our work sheds light on the reasons behind colony collapse and could help in the search for ways of preventing colony collapse.’
Colony collapse disorder (CCD) is a major threat to bee colonies – it has caused a 30 per cent average annual loss to honeybees in North America alone over the last decade – and ultimately to crop pollination. The main feature of the disorder is the complete disappearance of worker bees, which leaves the hive largely empty of adult bees. Its cause is still unknown, but scientists suggest that it may be the result of several factors interacting with one another.
Access the full report here: http://www.pnas.org/content/early/2015/02/04/1422089112