Do Beauveria bassiana and Metarhizium anisopliae affect worker survival and the production of Africanized Apis mellifera queens?

Abstract

The research aimed to evaluate the effect of Beauveria bassiana and Metarhizium anisopliae on Africanized Apis mellifera L. 1758 (Hymenoptera: Apidae). The application methods of entomopathogens suspensions were: 1) sprayed on eucalyptus leaves; 2) sprayed directly onto workers honey bees; and 3) incorporated in a candy paste. Sterilized distilled water that was offered to bees was used as a control. Each treatment consisted of five replicates of 20 bees. The longevity of the workers was checked from one to 144 hours. To study the effect of entomopathogenic fungi on morphometric parameters of produced queens, two cycles were performed: A) B. bassiana and control and B) M. anisopliae and control. For this, the transfer of worker larvae to acrylic domes containing royal jelly incorporated with the treatments was carried out. After nine days, the queen cells were placed in glass jars individually and stored in an acclimatized chamber until emergence, at which point the measurements of live weight were taken and morphometric analyses were performed. Beauveria bassiana caused a reduction in the survival of workers in the direct spray bioassay and when the entomopathogen was incorporated into the candy paste, while M. anisopliae caused a reduction in the survival in the three bioassays. The entomopathogenic fungi did not interfere negatively with the parameters evaluated for queens produced.