title: Chemical communication and host search inGalerucellaleaf beetles.
abstract: Herbivore insects use a variety of search cues during host finding and mate recognition, including visual, gustatory, and olfactory stimuli, leaving multiple traits for evolution to act upon. However, information about differences or similarities in search pattern amongst closely related insect herbivore species is still scarce. Here, we study the production of and the response to pheromone inGalerucella(Coleoptera: Chrysomelidae) to investigate the beetles' search behaviour. Males ofG.pusillaandG. calmariensis, two closely related species, are known to produce the aggregation pheromone dimethylfuran-lactone when feeding on their host plant, whereas no pheromones have been identified in otherGalerucellaspecies. We show that dimethylfuran-lactone is produced also by males ofG.tenella, a species phylogenetically close toG.pusillaandG.calmariensis, whereas the more distantly related speciesG. lineolaandG. sagittariaewere not found to produce the same compound. To investigate the beetles' behavioural response to dimethylfuran-lactone, the pheromone was synthesized using a partly novel method and tested in olfactometers, showing thatG.pusilla,G.calmariensis, andG.tenellawere all attracted to the pheromone, whereasG.lineolaandG.sagittariaedid not respond. This suggests that the production of and the response to pheromone could be linked to the phylogenetic relatedness between the species.
authors.affiliation: Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden.
authors.forename: Lisa
authors.initials: L
authors.lastname: Fors
authors.affiliation: Institute of Technology, University of Tartu, Tartu, 50411 Estonia.
authors.forename: Ilme
authors.initials: I
authors.lastname: Liblikas
authors.affiliation: Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden.
authors.forename: Petter
authors.initials: P
authors.lastname: Andersson
authors.affiliation: Department of Chemistry, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden.
authors.forename: Anna-Karin
authors.initials: AK
authors.lastname: Borg-Karlson
authors.affiliation: Department of Chemistry, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden.
authors.forename: Nancy
authors.initials: N
authors.lastname: Cabezas
authors.affiliation: Department of Chemistry, KTH Royal Institute of Technology, 100 44 Stockholm, Sweden ; Laboratory of Chemical and Behavioural Ecology, Institute of Ecology, Nature Research Centre, Akademijos 2, 08412 Vilnius, Lithuania.
authors.forename: Raimondas
authors.initials: R
authors.lastname: Mozuraitis
authors.affiliation: Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Hambäck
keywords: Olfactometer; Pheromone; Plant–herbivore interactions; Volatiles