Those social axes no longer recognize their colleagues

Wasp Polistes fuscatus have the ability to recognize the colored face of their relatives. In a new study published on April 14, 2021, researchers at Cornell University in the United States explain why they can lose that ability if placed in isolation.

The need for social relationships that allow the brain to mature

The Polistes fuscatus, Americans call them paper wasps, they are social insects that are especially found in the eastern United States. They live in relatively small colonies of up to several hundred members, while bees sometimes number in the tens of thousands. Another feature of paper wasp colonies is that they can have several queens. Every spring the latter can work together to make a nest. However, the sovereign is doing well in spite of everything: dominantly, she monopolizes the egg and puts her sisters to work. His subordinates can leave the nest and join another or find their own if the situation does not suit them. “There is a tension balancing the conflict between the cooperating queens and it seems to be the thing that has made individuals identify, namely who is who, how the job is divided, whether they will get their fair share, remark in Statement Michael Sheehan, co-author of this new study published in the journal Letters from biology. It seems to be helping to resolve the conflict.“Because”females Polistes fuscatus they demonstrate visual and individual recognition thanks to unique color patterns on their faces“, recalls the new research. But this recognition among relatives requires social experience for its development to take place properly. The visual brain areas involved are hitherto unknown, so they are sensitive to the presence of relatives and are not just a place of simply pre-programmed maturation.

These wasps can recognize colorful patterns of their peers. Credits: MJ Sheehan

An answer that is certainly found in the anterior ocular tubercle

Larvae from P. fuscatus they live in individual cells in the nest. They are able to detect chemical compounds and light, but their visual abilities stop here at this stage because their areas of the brain are not yet sufficiently developed. As some wasps emerged from their cocoons, the researchers separated them from the colony: some were placed in individual containers, while others were placed in the same containers but with different wasps. After two months, the scientists analyzed the brains of the insects that had become adults.

As with other social insects, we found that as P. fuscatus his old brain increases in size “, underlines the study. But the researchers also noted that some visual areas of the brain show volumetric changes associated with maturation and social experience. Thus, the optic lobe and anterior optic tubercle (AOT) “showed an increase in volume with age and social experience“Therefore, it is very possible for researchers that AOT – which receives its visual information from the optical flap and which is involved in color processing – is associated with.”processing of personal data and discrimination of persons“in paper axes. Future studies, anatomical and physiological, will be needed to confirm its role.

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