Controle biológico da cigarrinha Dalbulus maidis na cultura do milho (Zea mays)

Abstract

Maize is a very versatile grass as it provides, further the grain, the straw for next crops, which makes it one of the most used cereals in the world. The corn leafhopper Dalbulus maidis (Hemiptera: Cicadellidae) has been causing a lot of damage to producers, as it can cause direct damage by feeding on the sap, and indirect damage by being a vector of spiroplasma and phytoplasma, which cause the biggest problem, the stunting. Insect pests control has become increasingly difficult due to the misuse of insecticides. Biological control is one of the pillars of integrated pest management and, in this sense, the use of entomopathogenic fungi is increasing. The fungi Metarhizium anisopliae and Beauveria bassiana are the main biocontrol agents used for this purpose. The objective of this study is to evaluate the potential of the fungi Metarhizium anisopliae and Beauveria bassiana as biological control agents for the corn leafhopper. It was carried out in the experimental field of the Federal University of Pampa, Campus Itaqui, from October 2022 to January 2023. Two commercial biological products were evaluated, METIÊ® based on Metarhizium anisopliae and BOMETIL® based on Beauveria bassiana and Metarhizium anisopliae both registered to control of several species of insect for all crops, but with no references to Dalbulus maidis. For each product, the control efficiency was evaluated in four doses, in addition to the check without treatment, constituting five treatments per commercial product, totaling 10 treatments. The experimental design was randomized blocks with 4 replications. Applications were carried out on 11/25/2022 and 12/11/2023, and the evaluations were carried out at 3 and 7 days after the 1st application and at 3, 7 and 30 days after the 2nd application. To evaluate the number of live leafhoppers, a generalized linear model (GLM) adjustment was performed with a log link function, using R software. Both products were efficient in reducing the population of leafhoppers, despite the adverse weather conditions that occurred during the conduction of the experiment.