Behavioral responses of Bt -resistant and -susceptible Spodoptera frugiperda males to female sex pheromone

• Ano de defesa: 2016
• Autor(a) principal: De La Pava Suárez, Nataly
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Spodoptera frugiperda - Controle biológico; Bacillus thuringiensis; Comportamento reprodutivo; Seleção sexual; Millho - Cultivo; Entomologia Agrícola
• Link de acesso: https://locus.ufv.br//handle/123456789/26642

Spodoptera frugiperda is the most important economic pest of corn in tropical areas of the American continent. Genetically modified crops that produces Bacillus thuringiensis (Bt) toxins are the main strategy for the pest control. But, despite the use of resistance management strategy (refuge/high dose) on these crops, Bt-resistant insects can still be selected. This differential adaptation can lead to behavioral changes, for example, in the species- specific communication between Bt-resistant and -suceptible populations. An obstacle in finding a different genotype female could lead to a reduction of the efficacy of refuge strategy. Here we show that the reproductive behavior of S. frugiperda males changes when subjected to a selection pressure from a Bt crop. The flight behavior of Bt -resistant and -susceptible males towards female sex pheromone gland extract from both genotypes were evaluated in a wind tunnel. The males reached the source of odor in the higher frequency when tested with their own genotype pheromone. Cross-attraction between genotypes also occurred, but at a lower frequency. Susceptible males had a higher attraction to the resistant female pheromone than resistant males flying to susceptible female pheromone. Our results suggest that the selective pressure generated by Bt crops cause a reproductive isolation in 5. frugiperda populations and reduction of effectiveness of refuge strategy.