Bioinsecticidal correlation of two species of piper on Sitophilus zeamais (Coleoptera: Curculionidae)

Abstract

Introduction: The genus Piper has distribution mainly in tropical regions and phytochemical studies revealed the presence of amides, flavonoids and phenylpropanoids and insecticidal and larvicidal activities and can be an alternative for insect control, especially the coleopteran Sitophilus zeamais, reducing the application of commercial insecticides. Objectives: The goal of this study was to evaluate the susceptibility of S. zeamais to extracts of two species of the genus Piper. Methodology: The production of the extracts was made from plants fruits collected in the municipality of Chapadinha-MA, MA, Brazil. The efficacy of Piper tuberculatum and Piper callosum extracts against S. zeamais adults was investigated using different concentrations in the laboratory. Mortality was assessed 24 and 72 hs after exposure, the design used was completely randomized (DIC) with six treatments and four repetitions. Results: The results showed that the P. tuberculatum extract was the most potent, with 100% lethality at 24 hr. and 72 hr. posttreatment. The least toxic to S. zeamais was P. callosum extract with 78.7% mortality in the concentration of 20% in the period of 72 hs, with no significant results in the period of 24 hs. Conclusion: The fruits of P. tuberculatum could have potential for the development of novel bioinsecticide to control S. Zeamais, for use in an integrated pest management program, the same was not observed for the extract of P. callosum.

Keywords: Corn weevil; Bioinsecticide; Piper callosum; Piper tuberculatum.