Aspectos genéticos e comportamentais da resistência a Deltametrina em populações de Plutella xylostella (L.) (Lepidoptera : Plutellidae)

Detalhes bibliográficos
Ano de defesa: 2011
Autor(a) principal: SILVA, Wellington Marques da lattes
Orientador(a): BADJI, César Auguste
Banca de defesa: TEIXEIRA, Valéria Wanderley
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Federal Rural de Pernambuco
Programa de Pós-Graduação: Programa de Pós-Graduação em Entomologia Agrícola
Departamento: Departamento de Agronomia
País: Brasil
Palavras-chave em Português:
Palavras-chave em Inglês:
Área do conhecimento CNPq:
Link de acesso: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6036
Resumo: Plutella xylostella (L.) is one of the major pests of Brassica crops. The infestations in cultivated areas of Pernambuco and other states in Brazil have led farmers to frequently spray insecticides. The evolution of insecticide resistance can be pointed as one of the main problems in the control of this pest. This resistance may be associated with the target site alteration, particularly to pyrethroids. Aside from that, other resistance factors may also be related to inefficacy of products such as behavior, where the resistant individuals are able to avoid exposure to areas where the insecticide is present. This research objective was to verify whether a relationship exists between the frequency of the L1014F mutation in the sodium channel and the deltamethrin resistance ratios in populations of P. xylostella, as well as whether they have the ability to avoid exposure to this insecticide. P. xylostella populations were collected in the Agreste region of Pernambuco and Rio Grande do Sul States. Deltamethrin resistance ratios of P. xylostella field populations were compared with a laboratory population. Mortality data were subject to Probit analysis. The populations of P. xylostella showed a variable response and significant resistance to deltamethrin. The Belo Jardim, PE population showed the highest resistance ratio (10 - times) compared with the laboratory population. It was observed an increase of the RR genotype for L1014F mutation as the resistance increased. P. xylostella larvae were exposed to deltamethrin at field rate concentration (7.5 mg/L) and at their CL99s previously determined from bioassays, and their walking behavior evaluated by the Viewpoint® tracking system. The populations of Belo Jardim, PE and Bezerros, PE showed irritability behavior across all of the walking behavioral parameters analyzed.