Caterpillars detect predators by their static electricity

May 24. () –

Caterpillars respond defensively to electric fields similar to those emitted by their natural predatorsas scientists at the University of Bristol have discovered.

In the study, published in the journal PNASexperts showed that caterpillars’ hairs move in response to electric fields and are most sensitive to frequencies that correspond to the frequencies of the flapping wings of other insects, indicating that their hairs could be tuned to capture the electrical signals of their predators.

These findings are the first example of static electricity used as a sensory signal in a predator-prey interaction.

Lead author Dr. Sam England explained it’s a statement: “We knew that many animals naturally build up static electricity in their bodies as they move through their environment, and that static electricity can push and pull on other charged objects.

“In particular, we knew that insect hairs can move thanks to the electric field emitted by statically charged objects, in the same way that a charged balloon can move the hair on your head.

“This made us wonder: what if a prey animal, like a caterpillar, could detect its predators by sensing the electric field emanating from them? Would the static charge of a predator, like a wasp, push and pull the sensory hairs on a caterpillar enough to inform it of the wasp’s approach?

The team measured how much static charge the wasps and caterpillars carry by passing them through a static charge sensor. They then fed these charge values ​​into computer models to mathematically predict how strong the electric field would be. when a wasp approaches a caterpillar on a plant.

When the caterpillars responded defensively to these conditions, they were able to use a laser to detect small vibrations to investigate whether it was the sensory hairs that detected electricity, measuring how much they move in response to different electric field frequencies.

The study results are concerning because they show that caterpillars are also sensitive to electric field frequencies emitted by power lines and other electronic equipment. This means that humans may be hindering the animals’ ability to detect their predators. by filling the environment with electrical “noise.”

Dr England continued: “I would say that it now seems quite urgent to assess whether we are hampering the ability of caterpillars and other animals to detect their predators by introducing a new type of sensory pollution: electrical noise”.

Predator-prey interactions are a matter of life and death and, as such, are one of the main drivers of animal evolution. Almost all terrestrial animals appear to accumulate static charge, meaning that this sensation of static electricity may be widespread, and the discovery that static electricity plays a role in these ecological interactions opens entirely new dimensions to our understanding of how animals they feel each other, and more generally, how and why they evolve in certain ways.

Dr England added: “Our study shows that it is possible that terrestrial animals use static electricity as a predator detection signal.

“It is very likely that this is a very widespread ability, especially among insects and other small animals such as spiders and scorpions. This study presents the first example of an animal detecting its predators by sensing the static electricity emitted by the predator. This reveals a new dimension to predator-prey interactions on Earth, but also suggests a previously unnoticed way we might be negatively impacting wildlife: by introducing sources of electrical sensory pollution.