caa a22 4500 475838548 CHVBK 20180406123855.0 cr unu---uuuuu 170329e20000901xx s 000 0 eng 10.1007/PL00011996 doi (NATIONALLICENCE)springer-10.1007/PL00011996 Should aphids attract or repel ants? Effect of rival aphids and extrafloral nectaries on ant-aphid interactions [Elektronische Daten] [H. Sakata, Y. Hashimoto] Among plants and herbivores, two types of conflicts occur in relation to mutualism with ants: one is competition for ant mutualism among myrmecophilous herbivores and plants, and the other is the conflict whether to attract or repel ants between myrmecophiles and nonmyrmecophiles that are damaged by ants. We investigated the extent to which two species of aphids (Megoura crassicauda and Aphis craccivora) and extrafloral nectaries on their host plant (Vicia faba var. minor) interact with one another for their relationships with ants. We designed an experiment where ants can choose to visit seedlings colonized by (1) M. crassicauda, (2) A. cracivora, (3) both aphid species, or (4) neither aphid species. Ants preferred A. craccivora to extrafloral nectaries and avoided tending M. crassicauda. We also analyzed the population growth of each aphid when it coexists with (1) ants, (2) the other aphid species, (3) ants and the other aphid species, or (4) neither of them. Under ant-free conditions, we detected an exploitative competition between the two aphid species. The ants had no significant effect on the population of A. craccivora, whereas they had negative effects on the population growth of M. crassicauda by attacking some individuals. When both aphids coexisted, M. crassicauda suffered ant attack more intensely because A. craccivora attracted more ants than extrafloral nectaries despite ant-repelling by M. crassicauda. On the other hand, the ants benefited A. craccivora by eliminating its competitor. To avoid ant attack, aphids may have been selected either to be more attractive to ants than other sympatric sugar sources or to repel the ants attracted to them. We hypothesize that competition among sympatric sugar sources including rival aphids and extrafloral nectaries is a factor restricting aphids to be myrmecophilous. The Society of Population Ecology and Springer-Verlag Tokyo, 2000 Key words Interspecific relationships nationallicence Indirect interactions nationallicence Mutualism nationallicence Competition nationallicence Honeydew nationallicence Extrafloral nectary nationallicence Myrmecophily nationallicence Sakata H. Division of Ecology, Museum of Nature and Human Activities, Hyogo, 6 Yayoigaoka, Sanda 669-1546, Japan Tel. +81-795-59-2021; Fax +81-795-59-2015 e-mail: sakata@nat-museum.sanda.hyogo.jp, JP aut Hashimoto Y. Division of Phylogenetics, Institute of Natural and Environmental Sciences, Himeji Institute of Technology, Himeji, Japan, JP aut https://doi.org/10.1007/PL00011996 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/PL00011996 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sakata H. Division of Ecology, Museum of Nature and Human Activities, Hyogo, 6 Yayoigaoka, Sanda 669-1546, Japan Tel. +81-795-59-2021; Fax +81-795-59-2015 e-mail: sakata@nat-museum.sanda.hyogo.jp, JP aut NATIONALLICENCE 700 1- Hashimoto Y. Division of Phylogenetics, Institute of Natural and Environmental Sciences, Himeji Institute of Technology, Himeji, Japan, JP aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer