These findings are the first example of static electricity being used as a sensory cue in a predator-prey interaction. The team measured how much static charge wasps and caterpillars carry by having them pass through a static charge sensor. They then inputted these charge values into computational 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, there were able to use a laser to detect tiny vibrations to investigate whether it was the sensory hairs that were detecting the electricity, by measuring how much they move in response to different frequencies of electric field.

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

Read the full University of Bristol news story

Paper: ‘Prey can detect predators via electroreception in air’ by Sam J. England and Daniel Robert in PNAS.