Looking for a similar partner: host plants shape mating preferences of herbivorous insects by altering their contact pheromones

• Published in: Ecology letters Vol. 15; no. 9; pp. 971 - 977
• Main Authors: Geiselhardt, Sven, Otte, Tobias, Hilker, Monika
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.09.2012; Blackwell
• Subjects: Animal and plant ecology; Animal populations; Animal reproduction; Animal, plant and microbial ecology; Animals; Assortative mating; Biological and medical sciences; Coleoptera - genetics; cuticular hydrocarbons; ecological speciation; Ecology; Female; Fundamental and applied biological sciences. Psychology; Gene Flow; General aspects; Genotype & phenotype; Herbivores; Herbivory; Hydrocarbons; Insecta; Insects; Invertebrates; Male; Marriage; Phenotype; phenotypic plasticity; Pheromones; Pheromones - chemistry; Plant populations; Plants; Plants, Edible; sensory drive; sexual isolation; Assortative mating; sensory drive; Herbivorous; Hydrocarbon; ecological speciation; Insecta; sexual isolation; Phenotypic plasticity; Cuticle; Pheromone; Ecology; Contact; Mating; Reproduction; Preference; Arthropoda; Host plant; cuticular hydrocarbons; Invertebrata; Speciation
• ISSN: 1461-023X; 1461-0248
• DOI: 10.1111/j.1461-0248.2012.01816.x

The role of phenotypical plasticity in ecological speciation and the evolution of sexual isolation remains largely unknown. We investigated whether or not divergent host plant use in an herbivorous insect causes assortative mating by phenotypically altering traits involved in mate recognition. We found that males of the mustard leaf beetle Phaedon cochleariae preferred to mate with females that were reared on the same plant species to females provided with a different plant species, based on divergent cuticular hydrocarbon profiles that serve as contact pheromones. The cuticular hydrocarbon phenotypes of the beetles were host plant specific and changed within 2 weeks after a shift to a novel host plant species. We suggest that plant‐induced phenotypic divergence in mate recognition cues may act as an early barrier to gene flow between herbivorous insect populations on alternative host species, preceding genetic divergence and thus, promoting ecological speciation.