Exploration of kin selection theory with a solitary parasitoid wasp: relationship between relatedness among foundresses and extremely female-biased sex ratios

2015 Fiscal Year Final Research Report

• Project/Area Number: 24770029
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Ecology/Environment
• Research Institution: Kanagawa University
• Principal Investigator: Abe Jun 神奈川大学, 理学部, 助教 (70570076)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: 性比調節 / 適応度 / 進化 / 寄生バチ / Melittobia australica / 雄間闘争 / 遺伝構造 / 血縁度

Outline of Final Research Achievements

Sex allocation is one of the most successful areas in evolutionary biology. However, contrary to the prediction of theory, the females of Melittobia wasps produce extremely and constantly female-biased sex ratios (1-3% males). (1) An experiment that artificially manipulated offspring sex ratios and measured fitness showed that an observed sex ratio in Melittobia (about 2%) is not beneficial against higher sex ratios (about 10 or 20%) in a laboratory condition. This suggests that it is important to consider not only direct fitness but also indirect fitness with relatedness between ovipositing females on the same host in the field. (2) The females of Melittobia favored laying eggs on a host where other females have already been laying eggs, suggesting that females on a host could be sisters or relatives. (3) We developed microsatellite primers, which could be used for a future research analyzing population genetics to investigate the relatedness between ovipositing females in the field.

Free Research Field

進化生物学