O uso de fungos entomopatogênicos no controle de Tetranychus gloveri Banks (Prostigmata: Tetranychidae)

Abstract

The mites of the Tetranychidae family, such as Tetranychus gloveri Banks, cause significant damage to several crops, reducing productivity and, in more severe cases, causing the death of the plant. Chemical control is the most widely used method to control populations of pest mites. However, the excessive use of chemical acaricides has led to increased resistance, making it necessary to implement other control methods, such as biological control through entomopathogenic fungi. Thus, the objective of this study was to evaluate the lethal and sublethal effects of Metarhizium anisopliae and Beauveria bassiana on adult and immature females of T. gloveri by evaluating the mortality rate of females and immatures, the oviposition rate, and the preference for oviposition site of females. For this purpose, the mites were exposed to the residue of the application of fungi at concentrations of 1x10⁸ conidia/ml. The fungus Metarhizium anisopliae demonstrated high efficacy, causing 100% mortality in adult females and immatures on the 7th day of evaluation. Additionally, it significantly reduced oviposition to 2 eggs/female/day and altered the female's oviposition site choice behavior. In contrast, the fungus Beauveria bassiana did not cause significant mortality in females, no sublethal effect in immatures and did not cause alteration in site choice and oviposition behavior, however it reduced oviposition to approximately 5.7 eggs/female/day. Thus, among the fungi tested, M. anisopliae showed greater potential as a population control tool for T. gloveri and can be used in a management strategy.