The efficiency of commercial isolates of Beauveria bassiana (Bals.) Vuillemin and Metarhizium anisopliae (Metsch.) Sorok (Hypocreales: Cordycipitaceae, Clavicipitaceae) on the spider mite Tetranychus urticae Koch (Acari: Tetranychidae)

Abstract

We aimed to evaluate the efficiency of the commercial isolates ESALQ 634, of Beauveria bassiana (Bals.)
Vuillemin, and IBCB 425, of Metarhizium anisopliae (Metsch.) Sorokin, on Tetranychus urticae Koch. We used adult females of
T. urticae kept on jack bean plants (Canavalia ensiformis L.) in greenhouse. Commercial isolates were provided by Laboratório
Fitoagro de Controle Biológico Ltda. Leaf disks of jack beans were immersed in 10 mL of fungal suspensions for five seconds,
placed on filter papers, and kept at room temperature for 30 min. Fifteen adult females of T. urticae were then transferred to each
disk. The experimental design was completely randomized, consisting of seven repetitions and three treatments: two fungi (M.
anisopliae and B. bassiana, at concentration 1 x 107 spores/mL) and control (distilled water). On the sixth evaluation, fungi M.
anisopliae and B. bassiana showed corrected mortality of 100 and 97.4%, respectively, and confirmed mortality of 85.7 and
76.2%, respectively. In neither parameter did the species differ by Tukey test (P < 0.05). Therefore, the commercial isolates IBCB
425, of M. anisopliae, and ESALQ 634, of B. bassiana, were efficient in the control of T. urticae.