Shining fluorescent light on bee sperm could help explain colony survival

Christina Kotze, a researcher in invertebrate reproductive biology at the University of the Western Cape (UWC), and Gerhard van der Horst, emeritus professor at UWC, describe how pioneering methods of analysis developed by UWC's comparative spermatology group may ultimately be used to save the world's honeybees.

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FAST FACTS

Honeybees, which play a key role in the pollination of plants, including food crops, are dying off for reasons not fully understood.

Many scientists think that poor sperm quality, perhaps caused by environmental stressors, may be the main reason for so-called colony collapse.

Researchers at the University of the Western Cape are combining fluorescent microscopy and sperm analysis to study bee health and identify potential environmental stressors.

Form follows function. This is the principle that the design or shape of something, whether made by humans or in nature, should serve a purpose.

Honeybees' function is to pollinate plants, make honey, survive and reproduce. Along with other pollinators (birds, moths, butterflies, bats and many more) they are the unsung forces behind much of what people eat, drink and even wear. Animal pollinators are said to contribute to the production of 87 global crops in 200 countries, including 30% of the world's food crops. Their labours have been valued at around €153 billion (about R2,6 trillion).

But in one review paper, researchers suggest that at current rates of decline, the world will lose some 40% of its insect species, including bees, over the next few decades. Among the causes are widespread use of pesticides and habitat loss.

Bee colonies worldwide are collapsing. A 2012 to 2014 survey by the European Commission (the first of its kind) estimated that some countries were losing as many as a third of their colonies every year.

The threats to their survival make it urgent to understand the relationship between form and function in honeybees, particularly the sperm of the male bees (drones), the 'flying genitalia' of the bee world, as one researcher described them. That's because of the way bees mate and reproduce.