Monitoramento da suscetibilidade de Spodoptera frugiperda (J.E. Smith) (Lepidoptera: noctuidae) à Flubendiamida e ao Metomil no estado de Mato Grosso

Abstract

The monitoring of Spodoptera frugiperda (J.E. Smith) to flubendiamide and methomyl was carried out through ingestion bioassays by surface treatment of artificial diet with insecticide on plastic plates. Seventeen field populations were collected in important producing regions in the State of Mato Grosso during the 2017 harvest. Populations differed for all tested doses (P <0.001), with some showing a high amplitude in the mortality rate indicating heterogeneity. This amplitude is generated due to the presence of resistant and susceptible individuals in the same population, fomenting the emergence of resistant populations if the susceptibility is not restored or if the control method for this pest remains the same. Alto Garças, Diamantino, Nova Mutum and União do Sul were the municipalities with the lowest mortality rates for methomyl insecticide. Therefore, it is necessary to implement programs for the monitoring of resistance to methomyl and flubendiamide insecticides in the regions evaluated in this study and the awareness of the rotation of mechanisms of action in order to avoid the use of these insecticides, since chemical control is the most used for this pest.