Spiders home in on mating signals

Killer spiders are finding food by intercepting the vibrations used by some insects to attract mates.

Predators are already known to exploit the sight, sound and smell communications of their prey, but this is the first example that scientists have found of a predator using the vibrations to find prey.

Experts from Cardiff University’s School of Biosciences observed the spider species Enoplognatha ovate – a relative of the highly poisonous black widow spider – and found it picked up on vibrations used by insects, including leafhoppers, to lure a mate.

Meta Virant-Doberlet, who carried out the research, said: “Vibrational signalling is a widespread form of sexual communication between animals.

“By observing this behaviour, we have been able to see, for the first time, that spiders are able to exploit sexual vibrational communication signals as a means of tracking down their prey.”

Researchers found that when recordings of male leafhopper vibrational signals were played, the predatory spiders began homing in on the signal and searching for food.

The spiders appeared to have a preference for male leafhoppers over females, which scientists believe is because males emit louder, more complex signals during courtship. Virant-Doberlet added: “Predators have evolved to intercept the signals of their prey, but until now this was thought to be limited to visual, acoustic and chemical ways of communicating.

“This new discovery represents a previously-overlooked strategy for prey location and a major unrecognised driver in the evolution of both predators and prey.

“This is a very significant scientific advance, opening up a whole new area for scientific investigation.

“Vibrational signalling is widespread among invertebrates and it is highly likely that many predators have evolved to exploit it.”

The research, supported by a Marie Curie Fellowship funded by the EU, was published in the journal Molecular Ecology.