Selection of entomopathogenic fungi to control Varroa destructor (Acari: Varroidae)

摘要

The aim of this work was select entomopathogenic fungi tolerant to temperatures inside the brood area of honey bees ( Apis mellifera ) for to control Varroa destructor . For this purpose, 50 Beauveria bassiana (Balsamo) Vuillemin and 48 Metarhizium anisopliae (Metschn.) Sorokin isolates were evaluated at 30 and 35 oC. For each isolate, colony discs of 5 mm with mycelium were placed in the center of a Petri dish with Sabouraud dextrose agar (SDA) medium. The dishes were incubated at 30 and 35 °C, without light. Radial growth of each colony was measured daily. All the B. bassiana and M. anisopliae isolates presented a lineal growth rate at a temperature of 30 oC. However, at 35 oC, most of the isolates did not grow, except three B. bassiana and 14 M. anisopliae isolates (P V. destructor by applying a suspension of 10⁷ conidia mL^-1. The most effective isolate was M. anisopliae Qu-M845 (P = 0.0033) which produced 85% mortality. The pathogenic capacity of this isolate on V. destructor and its tolerance to hive conditions allows us to consider this strain as an alternative to control this pest.