2024-03-28T13:02:05Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/662862022-11-17T02:08:08Zhdl_2115_20046hdl_2115_138Color polymorphism in an aphid is maintained by attending antsWatanabe, S.Murakami, T.Yoshimura, J.1000040301874Hasegawa, E.open accessCreative Commons Attribution-NonCommercial 4.0 InternationalPolymorphismant attendanceaphidsbalancing selectioncolor morphsfrequency dependent selection486The study of polymorphisms is particularly informative for enhancing our understanding of phenotypic and genetic diversity. The persistence of polymorphism in a population is generally explained by balancing selection. Color polymorphisms that are often found in many insects and arthropods are prime examples of the maintenance of polymorphisms via balancing selection. In some aphids, color morphs are maintained through frequency-dependent predation by two predatory insects. However, the presence of color polymorphism in ant-attended aphids cannot be explained by traditional balancing selection because these aphids are free from predation. We examined the selective advantages of the existence of two color (red and green) morphs in the ant-attended aphid, Macrosiphoniella yomogicola, in fields. We measured the degree of ant attendance on aphid colonies with different proportions of color morphs. The results show that the ants strongly favor aphid colonies with intermediate proportions of the two color morphs. The relationship between the degree of ant attendance and the proportion of color morphs in the field is convex when aphid colony size and ant colony size are controlled. This function has a peak of approximately 65% of green morphs in a colony. This system represents the first case of a balancing polymorphism that is not maintained by opposing factors but by a symbiotic relationship.American Association for the Advancement of Science2016-09-07engjournal articleVoRhttp://hdl.handle.net/2115/66286https://doi.org/10.1126/sciadv.1600606276172892375-2548Science Advances29e1600606https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/66286/1/1600606.pdfapplication/pdf279.21 KB2016-09-07