A new methodology to evaluate the effect of insecticides on Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in flooded rice (Oryza saliva) was tested. Artificial infestations with fall armyworm larvae (3rd -4th instars) on rice field plots, fenced by metallic cages was used. Larval mortality was evaluated 48 hours after insecticide application by flooding the rice field and counting the floating surviving insects. Lambdacyalothrin CE (7.5 g/ha) and permethrin CE (25 g/ha) provided high larval control (> 95 %). Cifluthrin CE (7.5 g/ha) and deltamethrin CE (2.0 and 2.5 g/ha) caused less mortality (< 70%). The advantages of this new methodology are discussed.
Insecta; fall armyworm; chemical control
