(1st Place) Sustainable corn leafhopper management: Experience from Brazil

Corn is the most produced cereal in the world, and because it is cultivated in more than one season in nearly all regions of Brazil, it provides suitable conditions for the occurrence and attack of the corn leafhopper Dalbulus maidis (Hemiptera: Cicadellidae). The corn leafhopper is currently one of the main corn pests, especially because it is responsible for the transmission of mollicutes and virus. Its management is carried out mainly with chemical insecticides, usually with many sequential sprays, and there is an interest in developing more sustainable alternatives for the management of this pest, with biological insecticides being the most promising alternative. This study aimed to evaluate chemical and biological insecticides in the control of D. maidis in laboratory and field experiments.  In the laboratory conditions, the treatments were applied isolated, and, in the field, three management programs were performed with two sequential applications: biological, chemical and biological - chemical were tested in three areas of the state of Rio Grande do Sul. The results were submitted to analysis of variance (ANOVA) and Scott-Knott test (P≤0.05), revealing differences between treatments. The results of the management program with biological - chemical applications presented control between 42% and 67%, not statistically different from the exclusive chemical management, that had efficacy between 49% and 72%. In addition, in the bioassay, the minimum mortality among biological treatments was 77% in the final evaluation, showing the effectiveness of biological insecticides as an alternative control in the management of corn leafhopper.