title: Location-specific cuticular hydrocarbon signals in a social insect.
abstract: Social insects use cuticular hydrocarbons (CHCs) to convey different social signals, including colony or nest identity. Despite extensive investigations, the exact source and identity of CHCs that act as nest-specific identification signals remain largely unknown. Perhaps this is because studies that identify CHC signals typically use organic solvents to extract a single sample from the entire animal, thereby analysing a cocktail of chemicals that may serve several signal functions. We took a novel approach by first identifying CHC profiles from different body parts of ants (Iridomyrmex purpureus), then used behavioural bioassays to reveal the location of specific social signals. The CHC profiles of both workers and alates varied between different body parts, and workers paid more attention to the antennae of non-nest-mate and the legs of nest-mate workers. Workers responded less aggressively to non-nest-mate workers if the CHCs on the antennae of their opponents were removed with a solvent. These data indicate that CHCs located on the antennae reveal nest-mate identity and, remarkably, that antennae both convey and receive social signals. Our approach and findings could be valuably applied to chemical signalling in other behavioural contexts, and provide insights that were otherwise obscured by including chemicals that either have no signal function or may be used in other contexts.
authors.affiliation: School of BioSciences, University of Melbourne, Victoria 3010, Australia wangqike123@gmail.com.
authors.forename: Qike
authors.identifier: http://orcid.org/0000-0001-8012-027X
authors.initials: Q
authors.lastname: Wang
authors.affiliation: School of BioSciences, University of Melbourne, Victoria 3010, Australia.
authors.forename: Jason Q D
authors.identifier: http://orcid.org/0000-0001-7392-3891
authors.initials: JQ
authors.lastname: Goodger
authors.affiliation: School of BioSciences, University of Melbourne, Victoria 3010, Australia.
authors.forename: Ian E
authors.initials: IE
authors.lastname: Woodrow
authors.affiliation: School of BioSciences, University of Melbourne, Victoria 3010, Australia.
authors.forename: Mark A
authors.identifier: http://orcid.org/0000-0003-0861-6064
authors.initials: MA
authors.lastname: Elgar
mesh_terms: D000374:Aggression; D000819:Animal Communication; D000818:Animals; D001000:Ants / Q000502:physiology*; D057506:Arthropod Antennae / Q000502:physiology*; D006838:Hydrocarbons / Q000378:metabolism*; D012919:Social Behavior
chemical_list: D006838:Hydrocarbons
keywords: antennae; cuticular hydrocarbons; nest-mate recognition