title: Premating reproductive barriers between hybridising cricket species differing in their degree of polyandry.
abstract: Understanding speciation hinges on understanding how reproductive barriers arise between incompletely isolated populations. Despite their crucial role in speciation, prezygotic barriers are relatively poorly understood and hard to predict. We use two closely related cricket species, Gryllus bimaculatus and G. campestris, to experimentally investigate premating barriers during three sequential mate choice steps. Furthermore, we experimentally show a significant difference in polyandry levels between the two species and subsequently test the hypothesis that females of the more polyandrous species, G. bimaculatus, will be less discriminating against heterospecific males and hence hybridise more readily. During close-range mating behaviour experiments, males showed relatively weak species discrimination but females discriminated very strongly. In line with our predictions, this discrimination is asymmetric, with the more polyandrous G. bimaculatus mating heterospecifically and G. campestris females never mating heterospecifically. Our study shows clear differences in the strength of reproductive isolation during the mate choice process depending on sex and species, which may have important consequences for the evolution of reproductive barriers.
authors.affiliation: Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall, United Kingdom. veen@biodiversity.ubc.ca
authors.forename: Thor
authors.initials: T
authors.lastname: Veen
authors.forename: Joseph
authors.initials: J
authors.lastname: Faulks
authors.forename: Rolando
authors.initials: R
authors.lastname: Rodríguez-Muñoz
authors.forename: Tom
authors.initials: T
authors.lastname: Tregenza
mesh_terms: D000818:Animals; D002755:Choice Behavior; D005260:Female; D006135:Gryllidae / Q000502:physiology*; D006824:Hybridization, Genetic; D008297:Male; D012098:Reproduction / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013045:Species Specificity