Integrating management tactics to mitigate Spodoptera frugiperda resistance in Bt corn: refuge proportions, natural parasitoids, and selective insecticide application.

Autor: Tomé MP; Department of Entomology and Acarology, Luiz de Queiroz Agricultural College (ESALQ), University of São Paulo, Piracicaba, Brazil., Weber ID; University of Brescia, DICATAM, Brescia, Italy., Garcia AG; Department of Entomology and Acarology, Luiz de Queiroz Agricultural College (ESALQ), University of São Paulo, Piracicaba, Brazil., Godoy WA; Department of Entomology and Acarology, Luiz de Queiroz Agricultural College (ESALQ), University of São Paulo, Piracicaba, Brazil.
Jazyk: angličtina
Zdroj: Pest management science [Pest Manag Sci] 2024 Dec 12. Date of Electronic Publication: 2024 Dec 12.
DOI: 10.1002/ps.8584
Abstrakt: Background: Different approaches have been adopted to manage Spodoptera frugiperda resistance to Bt toxins. However, studying the synergism among these practices applied directly in crop fields is a major challenge. We used a computational model to investigate how the proportion of refuge strips [crop area occupied by non-Bt corn (maize): 5%, 10%, 15%, or 20%] and the presence of naturally occurring parasitoid, affected or not by a pesticide with different selectivities applied in the field, could influence the dynamics of the resistance allele (R) in a S. frugiperda population.
Results: Our model showed that proportions of 15% and 20% of non-Bt corn, together with parasitism, led to a reduction in the initial frequency of the R allele. However, the efficiency of the parasitoid depended on the selectivity of the insecticide. Simulations with 5% non-Bt corn and 50% selectivity, or without selectivity (0%), resulted in elimination of the parasitoid. In the absence of selection pressure, S. frugiperda larvae carrying at least one copy of the R allele showed higher susceptibility to parasitization.
Conclusion: Our findings suggest that parasitoids can potentially reduce the need for refuge zones, because they offset the reduction of non-Bt crops. Nevertheless, preservation of these benefical insects hinges upon the implementation of appropriate management practices by producers. Further investigations are warranted to corroborate these results, including the study of additional natural enemies. © 2024 Society of Chemical Industry.
(© 2024 Society of Chemical Industry.)
Databáze: MEDLINE
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