Wasps good at recognising each other’s faces

On a summer’s day, you would be getting the impression that annoying packs of them seem to buzz around at random in search of picnics to feast on.
But in fact wasps have friends who they recognise and behave aggressively towards strangers.

This is because unlike any other insect they have highly developed visual recognition ability and can remember the distinctive facial markings of other wasps.
Insects were previously thought to have brains too small and unsophisticated to recognise individuals, which involves processing a lot of information.
Scientists from the University of Michigan trained two groups of wasps to discriminate between two similar images mounted inside a T-shaped box.

They did 40 trials on each pair of pictures — photos of other wasps, a caterpillar, simple geometric patterns and computer-altered wasp faces.
The wasps could differentiate far more quickly between the unaltered images of a wasp than any of the others, and learned to pick the correct one three-quarters of the time.
When a small alteration is made using the computer, such as removing an antenna, they performed much worse on the facial recognition test.

They were not as good at recognising the simple black and white geometric patterns even though insect eyes are good at detecting contrast and outlines, lead author Michael Sheehan said.
The team have previously shown wasps can recognise each other after a week apart.
But this study, published in the journal Science, shows they are the only insect which can recognise faces and suggests recognising each other could be important to their hierarchy and the way they raise their offspring.

Wasps live in colonies of multiple queens which raise their offspring co-operatively and the authors suggest it could “keep individuals from wasting energy on repeated aggressive encounters” and promotes stability.

Mr Sheehan said: “Wasps and humans have independently evolved similar and very specialised face-learning mechanisms, despite the fact that everything about the way we see and the way our brains are structured is different. That’s surprising and sort of bizarre.
“It shows the way they learn faces is different than the way they seem to be learning other patterns which is striking.” — Daily Mail.