title: Aggressive mimicry coexists with mutualism in an aphid.
abstract: Understanding the evolutionary transition from interspecific exploitation to cooperation is a major challenge in evolutionary biology. Ant-aphid relationships represent an ideal system to this end because they encompass a coevolutionary continuum of interactions ranging from mutualism to antagonism. In this study, we report an unprecedented interaction along this continuum: aggressive mimicry in aphids. We show that two morphs clonally produced by the aphid Paracletus cimiciformis during its root-dwelling phase establish relationships with ants at opposite sides of the mutualism-antagonism continuum. Although one of these morphs exhibits the conventional trophobiotic (mutualistic) relationship with ants of the genus Tetramorium, aphids of the alternative morph are transported by the ants to their brood chamber and cared for as if they were true ant larvae. Gas chromatography-mass spectrometry analyses reveal that the innate cuticular hydrocarbon profile of the mimic morph resembles the profile of ant larvae more than that of the alternative, genetically identical nonmimic morph. Furthermore, we show that, once in the brood chamber, mimic aphids suck on ant larva hemolymph. These results not only add aphids to the limited list of arthropods known to biosynthesize the cuticular chemicals of their deceived hosts to exploit their resources but describe a remarkable case of plastic aggressive mimicry. The present work adds a previously unidentified dimension to the classical textbook paradigm of aphid-ant relationships by showcasing a complex system at the evolutionary interface between cooperation and exploitation.
authors.affiliation: Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Apartado de Correos 22085, 46071 Valencia, Spain;
authors.forename: Adrián
authors.initials: A
authors.lastname: Salazar
authors.affiliation: Institute of Biology, Applied Zoology/Animal Ecology, Freie Universität Berlin, 12163 Berlin, Germany;
authors.forename: Benjamin
authors.initials: B
authors.lastname: Fürstenau
authors.affiliation: Institute of Advanced Chemistry of Catalonia, Consejo Superior de Investigaciones Científicas, 08034 Barcelona, Spain;
authors.forename: Carmen
authors.initials: C
authors.lastname: Quero
authors.affiliation: Departamento de Biodiversidad y Gestión Ambiental, Universidad de León, 24071 León, Spain; and.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Pérez-Hidalgo
authors.affiliation: Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Apartado de Correos 22085, 46071 Valencia, Spain; Edward Grey Institute, Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom.
authors.forename: Pau
authors.initials: P
authors.lastname: Carazo
authors.affiliation: Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Apartado de Correos 22085, 46071 Valencia, Spain;
authors.forename: Enrique
authors.initials: E
authors.lastname: Font
authors.affiliation: Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Apartado de Correos 22085, 46071 Valencia, Spain; david.martinez@uv.es.
authors.forename: David
authors.initials: D
authors.lastname: Martínez-Torres
mesh_terms: D000818:Animals; D001000:Ants / Q000502:physiology; D001042:Aphids / Q000502:physiology*; D001483:Base Sequence; D008401:Gas Chromatography-Mass Spectrometry; D008018:Life Cycle Stages / Q000502:physiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D013559:Symbiosis / Q000502:physiology*
keywords: aggressive mimicry; ants; aphids; mutualism; polyphenism