Butterfly mimics 'talk' like ants

To most people the idea that ants communicate using sound is pretty surprising.

So how much more surprising is that these ant sounds (in particular queen ant sounds) are mimicked by the pupae and caterpillars of an ant parasite: the Rebel's Large Blue butterfly?

As The Times, amongst others, reports this is exactly what a team including Oxford's Jeremy Thomas have demonstrated in research published in this week's Science.

The original idea came to Jeremy some 15 years ago when he was recording the stridulations of worker ants and caterpillars and noticed similarities between calls of certain species. He realised that these sound signals might explain his observation that sometimes worker ants treated the caterpillars like ants queens when the caterpillar's chemical and behavioural signals only mimicked those of ordinary ants.

However, it would be over a decade before audio equipment was sophisticated enough to prove whether or not the idea was correct. 

The team tested the theory by recording and then playing back the sounds made by queen ants to workers in a nest. Jeremy told Lewis Smith in The Times: 'When we played the queen sounds they did 'en garde' behaviour. They would stand motionless with their antennae held out and their jaws apart for hours - the moment anyone goes near they will attack.'

In short, the right sound signals cause workers to protect and care for an invading caterpillar as if it is their queen.

Such a discovery is especially important because the Rebel's Large Blue (Maculinea rebeli) is an endangered species, Jeremy notes: 'The new findings will play a key part in designing a successful science-led conservation strategy... Any such strategy must be based on an excellent understanding of the intimate interactions between the butterfly and its ant host.'

'There is also an urgent need to investigate whether acoustical mimicry has evolved among other, rare, social parasites that infiltrate and exploit ant societies.'

Professor Jeremy Thomas is Professor of Ecology at Oxford's Department of Zoology and a Professorial fellow of the Centre for Ecology & Hydrology

The work was carried out by researchers from Oxford University, the Centre for Ecology & Hydrology and scientists from the University of Turin, Italy.