Dancing hairs alert bees to floral electric fields

Date: May 30, 2016

Source: University of Bristol

Tiny, vibrating hairs may explain how bumblebees sense and interpret the signals transmitted by flowers, according to a study by researchers at the University of Bristol.

Although it's known that flowers communicate with pollinators by sending out electric signals, just how bees detects these fields has been a mystery -- until now.

Using a laser to measure vibrations, researchers found that both the bees' antenna and hairs deflect in response to an electric field, but the hairs move more rapidly and with overall greater displacements.

Researchers then looked at the bees' nervous system, finding that only the hairs alerted the bee's nervous system to this signal.

The findings, published in the international journal Proceedings of the National Academy of Sciences (PNAS) today, suggest that electroreception in insects may be widespread.

Electroreception may arise from the bees' hairs being lightweight and stiff, properties that confer a rigid, lever-like motion similar to acoustically sensitive spider hairs and mosquito antennae.

Dr Gregory Sutton, a Research Fellow in the University of Bristol's School of Biological Sciences, led the research. He said: "We were excited to discover that bees' tiny hairs dance in response to electric fields, like when humans hold a balloon to their hair. A lot of insects have similar body hairs, which leads to the possibility that many members the insect world may be equally sensitive to small electric fields."

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Bumblebees sense flowers' electric fields

By Ben Aviss, Reporter, BBC Nature

Bumblebees (Bombus terrestris) can detect flowers' electric fields, scientists have discovered.

Results indicate floral electric fields improve the bees' ability to discriminate between different flowers.

When used with visual signals, electrical cues can enhance the bee's memory of floral rewards.

Researchers suggest this method of signalling provides rapid and dynamic communication between plants and pollinators.

The findings are published in the online journal Science Express.

Flowering plants reward pollinators with nectar and pollen in return for their assistance in the flowers' sexual reproduction.

Flowers attract pollinators using cues such as bright colours, patterns and enticing fragrances but this study suggests the importance of electrostatic information as an additional cue for the first time.

"Of course it has existed for a long time but this is a new way we can look at the interactions between bees and flowers," said Prof Daniel Robert of the University of Bristol.

Continued:  http://www.bbc.co.uk/nature/21508035

Shark embryos 'freeze' to evade predators

Bamboo shark embryos developing in egg cases stay still to evade predators, scientists say.

Australian researchers found that the embryos could identify electric fields simulating a nearby predator, despite being confined to a tiny egg case.

On sensing danger, they "froze" and temporarily stopped breathing to avoid being detected.

Sharks use jelly-filled pores on their heads called electroreceptors to recognise other animals.

These highly sensitive receptors enable sharks to locate prey, predators or potential mates from minute bioelectric fields.
The study, by scientists from the University of Western Australia, Crawley, near Perth, suggests brownbanded bamboo shark (Chiloscyllium punctatum) embryos are able to employ similar methods to detect predators.

"Embryonic sharks are able to recognise dangerous stimuli and react with an innate avoidance response," explained Ryan Kempster, a shark biologist and member of the research team.

The team's findings are published in the journal PLoS ONE.

Brownbanded bamboo sharks grow up to 1.2m (3.9ft) in length and are found in the Indo-West Pacific region as well as coastal areas of northern Australia and southern New Guinea.

Continued: http://www.bbc.co.uk/nature/20945543