title: Mutualisms and population regulation: mechanism matters.
abstract: For both applied and theoretical ecological science, the mutualism between ants and their hemipteran partners is iconic. In this well-studied interaction, ants are assumed to provide hemipterans protection from natural enemies in exchange for nutritive honeydew. Despite decades of research and the potential importance in pest control, the precise mechanism producing this mutualism remains contested. By analyzing maximum likelihood parameter estimates of a hemipteran population model, we show that the mechanism of the mutualism is direct, via improved hemipteran growth rates, as opposed to the frequently assumed indirect mechanism, via harassment of the specialist parasites and predators of the hemipterans. Broadly, this study demonstrates that the management of mutualism-based ecosystem services requires a mechanistic understanding of mutualistic interactions. A consequence of this finding is the counter intuitive demonstration that preserving ant participation in the ant-hemipteran mutualism may be the best way of insuring pest control.
authors.affiliation: Department of Integrative Biology, University of Texas, Austin, Texas, United States of America. sjha@austin.utexas.edu
authors.forename: Shalene
authors.initials: S
authors.lastname: Jha
authors.forename: David
authors.initials: D
authors.lastname: Allen
authors.forename: Heidi
authors.initials: H
authors.lastname: Liere
authors.forename: Ivette
authors.initials: I
authors.lastname: Perfecto
authors.forename: John
authors.initials: J
authors.lastname: Vandermeer
mesh_terms: D000818:Animals; D001000:Ants / Q000254:growth & development / Q000502:physiology; D055669:Ecological and Environmental Phenomena; D017753:Ecosystem; D005298:Fertility; D006430:Hemiptera / Q000254:growth & development / Q000502:physiology; D011157:Population Dynamics; D011235:Predatory Behavior