Inheritance and fitness costs ofSpodoptera frugiperda(Lepidoptera: Noctuidae) resistance to spinosad in Brazil

Autor: Renato J. Horikoshi, Daniel Bernardi, Daniela M. Okuma, Celso Omoto, Aline de Seixas Pinto da Silva, Oderlei Bernardi
Rok vydání: 2018
Předmět:
Zdroj: Pest Management Science. 74:1441-1448
ISSN: 1526-498X
DOI: 10.1002/ps.4829
Popis: BACKGROUND Spodoptera frugiperda is a pest of economically important crops in South America. In Brazil, this species is considered the most destructive pest of maize. Use of spinosyn insecticides in insect resistance management (IRM) has been one strategy to control this pest. In this study, we selected a strain of S. frugiperda resistant to spinosad and evaluated the inheritance and fitness costs of the resistance. RESULTS Estimated LC50 (concentration required to kill 50% of larvae) values were 0.011 and 9.80 µg cm-2 for the spinosad-susceptible (Sus) and -resistant (Spin-res) strains, respectively. This represents an 890-fold resistance ratio. LC50 values for reciprocal crosses were 0.18 and 0.14 µg cm-2 , indicating that resistance to spinosad is an autosomal incompletely recessive trait. Backcrosses of the F1 progeny from reciprocal crosses with the parental Spin-res strain showed a polygenic effect. The estimated minimum number of independent segregations was ∼ 2.45, indicating that resistance to spinosad is associated with multiple genes. In greenhouse assays, third-instar larvae from the Spin-res strain showed >92% survival on spinosad-treated maize. By contrast Sus and reciprocal crosses exhibited 0% and
Databáze: OpenAIRE
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