Development of an attract-and-infect system to control Rhynchophorus ferrugineus with the entomopathogenic fungus Beauveria bassiana

Abstract

[EN] BACKGROUNDA new Beauveria bassiana-based attract and infect device (AID) to control Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) was developed. The virulence and persistence of the fungal formulation used in the AID were evaluated in the laboratory. Semi-field and field trials were carried out to validate the results and establish the potential of this device as a control tool.

RESULTSIn laboratory conditions, a 50% lethal time (LT50) of 4.33 days was obtained when adults (7-10 days old) were exposed to the inoculation tunnel (IT) containing 1 x 10(10) conidia g(-1) in an oil-based fungal formulation. This formulation maintained conidium viability at 50% for up to 2 months. Moreover, when adults were exposed to 2.5-month field-aged ITs, mortality still reached 50% 40 days after exposure. In addition, no differences were observed between ITs aged in early spring and those aged in summer, suggesting that the fungal formulation is not strongly affected by environmental factors in Mediterranean basin conditions. Semi-field assays showed that the device allowed an easy transit of weevils through the IT, which were effectively attracted and infected. Using the AIDs in 4-ha plot field trials, a reduction of >50% in the percentage of infested sentinel palms was obtained.

CONCLUSIONBased on the results obtained in terms of the efficacy and persistence of this new AID in the field and its potential in reducing R. ferrugineus populations and palm infestation, this device could become a key tool for the management of R. ferrugineus. (c) 2018 Society of Chemical Industry