May 11, 2021
Meiji Gakuin University
RIKEN
Gifu University, Tokai National Higher Education and Research System
Keio University
Associate Professor Yoshitaka Kamimura of the Faculty of Business and Commerce, Keio University, together with Jun Abe, a researcher at the institute affiliated with the Center for Liberal Arts at Meiji Gakuin University; Ryosuke Iritani, a researcher at the RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program; Koji Tsuchida, a professor at the Faculty of Applied Biological Sciences, Gifu University; and Stuart A. West, a professor at the University of Oxford, has solved the mystery of wasps that produce only a few percent of males.
• While the reason why wasps of the genusMelittobiaproduce extremely few males was previously unknown, this study has revealed it to be a form of cooperative behavior among co-founding mothers to efficiently produce offspring.
• InMelittobia, mothers adjust the ratio of males and females they produce based on their kinship with other co-founding mothers, producing extremely few males when laying eggs with related mothers.
• DNA analysis and mathematical theoretical analysis have shown that by producing fewer males, they can avoid wasteful competition for mates among related sons and produce more females instead, thereby increasing the number of offspring for each other.
• It was suggested that mothers cannot directly recognize kinship but instead indirectly estimate it based on their own dispersal experience: whether they dispersed locally (high chance of encountering relatives) or distantly (low chance of encountering relatives).
These research findings were published online inPNAS(Proceedings of the National Academy of Sciences) at 3:00 p.m. EDT on Monday, May 10, 2021 (4:00 a.m. JST on Tuesday, May 11).
Please see below for the full press release.