Bioatividade do óleo essencial de Cymbopogon citratus (DC.) Stapf sobre Dalbulus maidis (DeLong & Wolcott) (Hemiptera: Cicadellidae)

Abstract

In the corn crop, Dalbulus maidis is considered one of the main pests, as well as an insect vector of mollicutes and viruses responsible for phytopathogenic diseases, reducing productivity by more than 70%. Currently, its control is carried out using chemical insecticides, which have toxic effects on non-target organisms and also promote the development of resistance in target organisms, further limiting and making it difficult to control these insect pests. This work aimed to evaluate the bioinsecticide potential of Cymbopogon citratus essential oil in concentrations of 0.1; 0.5; 1.0; 1.5; and 2.0% v/v as an alternative to conventional products on adult individuals of D. maidis, as well as the use of two controls: one positive, composed of the chemical insecticide Perito 070 SG (acephate) at a dose of 1 kg/ha and two negative controls, Tween 80® 0.5% v/v and distilled water. The bioassays were performed in triplicate, with three replicates of ten individuals per treatment, totaling 30 individuals per treatment. Maize plants (stage V2-V3) were placed in bottles with a capacity of 2 L and 10 adults individuals (7-9 days) were put; the treatments were sprayed and covered with voile fabric. It was observed at concentrations of 0.1%; 0.5% and 1.0% there was no statistically significant difference in relation to the negative control in the 24 h, 48 h and 72 h assessments, whereas at the concentrations of 1.5% and 2.0% v/v there was a statistically significant difference from the negative control in the 24 h, 48 h and 72 h evaluations, showing mortality similar to the positive control, being a potential biopesticide in the control of D. maidis and a strong candidate for bioherbicide in the control of volunteer corn plants due to having caused toxicity to from concentrations of 1.0% v/v. [resumo fornecido pelo autor]