Honeybees are living half as long as they were 50 years ago, maybe unexpected consequence

 

https://www.newscientist.com/article/2346681-honeybees-are-living-half-as-long-as-they-were-50-years-ago/

 

14 November 2022
By Gary Hartley

 

Honeybees kept under laboratory conditions in the US only live half as long as they did in the 1970s, suggesting that genetics could be contributing to colony losses, and not just environmental factors such as pesticides and sources of food.

Five decades ago, the median lifespan for a worker western honeybee (Apis mellifera) that spent its adult life in a controlled environment was 34.3 days. Now, the median is 17.7 days, according to research by Anthony Nearman and Dennis vanEngelsdorp at the University of Maryland.

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 The change implies that solutions to the reduced life of colonies in the field, a problem increasingly encountered by beekeepers, may be found in the bees themselves.

“For the most part, honeybees are livestock, so beekeepers and breeders often selectively breed from colonies with desirable traits like disease resistance,” says Nearman.

“In this case, it may be possible that selecting for the outcome of disease resistance was an inadvertent selection for reduced lifespan among individual bees,” he says. “Shorter-lived bees would reduce the probability of spreading disease, so colonies with shorter lived bees would appear healthier.”

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Experimental honeybees are collected from hives as pupae within 24 hours of emerging from their wax cells, meaning that early exposure to pathogens or pesticides as larvae can’t be ruled out as a factor. However, the bees used in the current study showed no overt symptoms of such exposure, says Nearman.

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Further research will look at lifespan trends across different parts of the US and around the world, in an attempt to compare the relative impact of genetic and environmental factors.

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