POTENTIAL USE OF ENTOMOPATHOGENIC FUNGI IN THE CONTROL OF TETRANYCHUS URTICAE KOCH (ACARI: TETRANYCHIDAE) IN PAPAYA: CULTIVAR EFFECT ON PATOGENICITY

ABSTRACT Papaya Carica papaya (L.) is affected by various phytosanitary problems, and the mite Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae) is a key pest. The use of entomopathogenic fungi is an alternative to the use of pesticides, lowering the risk of resistance while reducing the the load of toxic substances in the environment. This study was conducted to determine whether the different cultivars of papaya interfere with the pathogenicity of Beauveria bassiana. Metarhizium anisopliae and Lecanicillium longisporum. The bioas say was carried out using adult T. urticae females maintained for at least one generation on leaves of four papaya cultivars (Calimosa, Golden, Sunrise, Tainung 01) or on jack bean leaves (control). Ten females were transferred to Petri dishes with leaf disks of the origin cultivars and jack beans. The mites were then sprayed with a 5 x 107 conidia.mL-1 suspension in a Potter Tower. Conidial suspensions were prepared from the commercial formulations Boveril® B. bassiana, Metarril® M. anisopliae, and Vertirril® L. longisporum. The corrected and confirmed mortalities were evaluated. Differences were observed (Tukey, P < 0.05) among the papaya cultivars in terms of the T. urticae pathogenic response. On the 3rd day after spraying (DAS), a better efficiency in mortality percentage was observed for the Vertirril® formulation applied to the Calimosa, Golden and Sunrise cultivars, and for Metarril® applied to the Tainung 01cultivar. On the 5th DAS, the efficiencies among the cultivars were very close.