The first inspection of 2017 has revealed that our bee colony has been devastated – they had all, sadly, died over the winter. The reason why the whole colony should die at once is unclear, but it is known as a ‘colony collapse disorder’ or CCD.
Scientists reckon CCD might be caused by a combination of factors interacting with one another, including exposure to agricultural pesticides and attacks by bee parasites such as varroa mites. We don’t know whether our bees have been exposed to pesticides, but they were checked for varroa before winter and got a clean bill of health. Our local bee expert, Andrea Ku, thinks it might be down to the weather, as we didn’t have a particularly cold season and they may have woken up too early.
However, some research suggests the suddenness of a colony’s collapse could to be related to a change in foraging behaviour whereby younger worker bees leave the hive in search of food rather than gaining more experience in the safety of the nest. Clint Perry, a researcher at Queen Mary University, London, said: “Young bees leaving the hive early is likely to be an adaptive behaviour to a reduction in the number of older foraging bees. But if the 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.”
“Precocious foragers completed far fewer foraging trips in their life, and had a higher risk of death in their first flights. This resulted in a breakdown in division of labour and loss of the adult population, leaving only brood, food and a few adults in the hive,” said researchers. A mathematical model found that as more workers started foraging at an earlier age, the effect had a positive feedback, with the change in behaviour causing more and more young workers to leave the hive, the researchers said.
Colony collapse disorder has caused a 30 per cent average annual loss of honeybees in North America alone over the last decade. A key feature of the disorder is the complete disappearance of worker bees, leaving the hive largely empty of adult bees. “Our results suggest that tracking when bees begin to forage may be a good indicate of the overall health of a hive. Our work sheds light on the reasons behind colony collapse and could help in the search for ways of preventing colony collapse,” Dr Perry said.
But all is not lost. Our hive will be thoroughly cleaned and a new colony will be in residence within the month. We go again!