麻豆传媒

Wasps can remember each other after a busy week apart, according to new research. It鈥檚 a level of social memory never seen before in insects, which were long thought to be too small-brained for such a feat.

Queens of the paper wasp, Polistes fuscatus, form cooperative nests after fighting to establish a dominance hierarchy.

When big-brained vertebrates like primates fight to establish dominance, they benefit from their ability to remember previous adversaries. But insects, even those with complex social colonies, were thought to lack that kind of individual social intelligence.

and at the University of Michigan in Ann Arbor, tested that idea.

Tibbetts knew that wasps can recognise individuals based on colour patterns on their faces. The next step was to see if they could remember individuals over a period of time in which they were distracted by other social interactions.

Buzz off, stranger

The researchers exposed female wasps to a new individual and then placed them in separate cages along with 10 other wasps. After one week, the females acted much more aggressively when placed with another new individual than when placed with the wasp they had met before.

鈥淚t鈥檚 about how many new memories and new experiences you can have before the first memory goes out the window,鈥� says Sheehan. 鈥淚n this case the wasps are remembering someone they interacted with at the same time as they鈥檙e interacting with 10 other wasps.鈥�

鈥淭his shows how we used to underestimate insect learning and cognition,鈥� says , an evolutionary biologist at McMaster University in Ontario, Canada, who studies insect learning.

鈥淭he biased view that you need a giant brain to be smart is not fully correct. Animals with small brains can do much more than we used to attribute to them.鈥�

Journal reference: (vol 18, R2)