Incipient allochronic speciation in the pine processionary moth (Thaumetopoea pityocampa, Lepidoptera, Notodontidae).
A plausible case of allochronic differentiation, where barrier to gene flow is primarily attributable to a phenological shift, was recently discovered in Portugal for the pine processionary moth Thaumetopoea pityocampa. Previous results suggested that the observed 'summer population' (SP) originated from the sympatric winter population (WP). Our objectives were to finely analyse these patterns and test their stability in time, through field monitoring and genetic analyses of larvae and adults across different years. Reproductive activity never overlapped between SP and WP. Microsatellites showed a clear differentiation of the SP, consistent with a strong reduction in gene flow owing to the phenological shift. Assignment tests suggested that some individuals shift from the SP to the WP phenology, causing some hybridization. We discuss these patterns and their maintenance over time. This could be a first stage of allochronic speciation, and SP should be considered as a distinct phenological race.
Centro de Estudos Florestais, Instituto Superior de Agronomia, Technical University of Lisbon, Lisboa, Portugal.
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Santos
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Burban
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Rousselet
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Rossi
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Branco
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Kerdelhué
D025041:Animal Migration; D000818:Animals; D005426:Flight, Animal; D018703:Founder Effect; D051456:Gene Flow; D049810:Genetic Speciation; D005838:Genotype; D006824:Hybridization, Genetic; D007814:Larva / Q000235:genetics; D018895:Microsatellite Repeats; D009036:Moths / Q000235:genetics* / Q000502:physiology; D012621:Seasons; D012726:Sexual Behavior, Animal