Effects of kinships of predators on community

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06849
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 45040:Ecology and environment-related
• Research Institution: Chiba University
• Principal Investigator: Yasuyuki Choh 千葉大学, 大学院園芸学研究院, 准教授 (90595571)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 捕食者ー被食者間相互作用 / 血縁認識 / 捕食回避行動 / ギルド内捕食 / 母性効果

Outline of Final Research Achievements

The predatory mite, Gynaeseius liturivorus, better protected own eggs than eggs laid by other females. When two sisters of G. liturivorus were kept with Neoseiulus californicus and Frankliniella occidentalis that could feed on G. liturivorus eggs, their reproduction was higher than that of conspecific non-sisters. Sisters of G. liturivorus stayed close to the eggs longer than non-sisters, suggesting that G. liturivorus sisters protect own eggs against egg predators cooperatively. When two groups of kin or non-kin G. liturivorus was kept with N. californicus and F. occidentalis separately, there was no difference in the abundance of each animal species. This study emphasize the importance of other factors that weaken the strength of predation on the coexistence of a community besides genetic variations among predator individuals.

Free Research Field

行動生態学

Academic Significance and Societal Importance of the Research Achievements

本研究は、キイカブリダニが他個体の卵よりも自分の卵を守ること、同じ餌を利用する捕食者（ギルド内捕食者）ミヤコカブリダニが存在する状況では姉妹で助け合って繁殖することを明らかにした。一般に同じ餌を利用し互いを捕食し合う生物種の共存は難しいことが先行研究で示されているが、本研究の結果は捕食を弱めることで両者の共存につながるメカニズムとして重要であると考えられる。一方、キイカブリダニは農業害虫のアザミウマ類の天敵としても注目されており、本研究の成果は、キイカブリダニ集団内の遺伝的な違いの低さが農業現場で高い増殖率を実現する上で有利に働く可能性を示すものである。