Toxicity and synergism of Piper aduncum L. essential oil on insect pests of stored productsThe Amazon Rainforest concentrates a large biodiversity with potential for research on botanical insecticides. Therefore, the management of stored grain pests can benefit, since control is predominantly carried out by synthetic insecticides, which makes it essential to search for alternative methods. Thus, the objective of this study was to evaluate the toxicity of Piper aduncum L. essential oil (PAEO) and its synergistic effect in mixtures with deltamethrin on Sitophilus zeamais Motschulsky, Oryzaephilus surinamensis (L.), Cryptolestes ferrugineus (Stephens) and Tribolium castaneum (H.). For this purpose, contact toxicity bioassays were performed on contaminated surfaces to generate concentration-mortality curves and establish lethal concentrations for 50 and 95% of the insects (LC50 and LC95). Subsequently, binary mixtures between PAEO and the insecticide were tested to determine the synergistic factor. There was variation in response among the four weevil species, both for PAEO and deltamethrin, with T. castaneum showing greater tolerance to both. PAEO potentiated the toxicity of deltamethrin for the four species, with synergism factors ranging from 1.42 to 6.30. It was concluded that the toxicity of PAEO varied among the four weevil species evaluated, with T. castaneum showing greater tolerance. Additionally, PAEO showed a synergistic effect in mixtures with deltamethrin.
Keywords:
Botanical insecticides; Piperaceae; Beetles; Post-harvest losses.
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