Drowsy bees can’t dance

U. TEXAS-AUSTIN (US) — Sleep-starved honey bees perform a less precise version of the waggle dance, a movement that tells hive mates where food is located.

This sluggish behavior could have long-term effects on colony survival, new research shows.

“When deprived of sleep, humans typically experience a diminished ability to perform a variety of tasks, including communicating as clearly or as precisely,” says Barrett Klein, a researcher at Universität Würzburg in Germany. “We found that sleep-deprived honey bees also experienced communication problems. They advertised the direction to a food site less precisely to their fellow bees.”

Klein invented a magnetic machine aptly named the “insominator,” a contraption he passed over quietly resting bees during the night to deprive them of sleep. The bees, outfitted with small metallic backpacks, were jostled into activity by magnets in the insominator, and this was repeated over the course of normal sleep time.

Barrett then recorded the behaviors of the sleepless bees and discovered they weren’t able to communicate as well the direction of nectar-filled flower patches to their sisters through their usual waggle dance.

“The dance was not necessarily wrong, but it was less precise than dances performed by bees that were not sleep-deprived,” says Klein.

For humans, imprecise communication can reduce efficiency, cost money, and in some cases, cost lives. For honey bees, Klein says it could affect their success in locating food, which could lead to a less competitive colony. “We expect that a less precise dance would lead to fewer followers making it to the food source, and we hope to test this in the future.”

“While the importance of sleep has been studied in Drosophila flies for several years,” says Ulrich Mueller, professor of biology at the University of Texas at Austin and coauthor of the study reported in PNAS Early Edition. “Barrett’s study is the first to address the function of sleep in a social insect in the context of its society, and the first to show that sleep deprivation impairs precision of communication in an insect.”

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