The efficacy of the Entomopathogenic Fungus, Beauveria bassiana , in Date Palm Protection against the Red Palm Weevil, Rhynchophorus Ferrugineus , Under Hot Dessert Climate

The Red Palm Weevil (RPW) is a devastating pest to palm trees. Commonly used insecticides for its control, can be harmful to the environment and humans. Moreover, some populations of the Red Palm Weevil have developed resistance to these compounds. Lab and semi-field data showed that Entomopathogenic fungi (EPF) can be a non-toxic and effective solution to reducing these pest infestations. However, the efficacy of EPF against the RPW has not been demonstrated in date palms on field trials with their variables. This study aims to examine the impact of various climate conditions the survival and efficacy of EPF Beauveria bassiana ( B. bassiana ) in prophylactic applications against the RPW in males and females Date palm groves cultivated using different agricultural practices. Healthy Date palms from the “Arava” region in Israel were selected and equipped with “IoTree” sensors to monitor RPW infestation. At the beginning of each season, the experimental group palms were treated with B. bassiana emulsions, while the control group was left untreated. Soil samples were gathered at the beginning and end of each season in both groves to quantify EPF survival rates and test their regression with EPF prophylactic treatments efficacy. Results showed significant effect for the season, on EPF treatments prophylactic efficacy, in the male and female groves. Generally, EPF treatments applied in the autumn season showed significant higher efficacy, while in the summer, the opposite results observed. Analysis of the results for males and females groves separately, displayed superiority for the spring season treatments on the males grove, and higher efficacy for autumn treatments on the females grove. Climate index significantly affects EPF treatment effectiveness. Analysis of soil tests at the end of each season revealed positive association between the number of B. bassiana fungus Colony-Forming units (CFUs) detected in the soil and the number of healthy palms within each group. Further research is needed to investigate the survival of EPF in various timeframes and explore diverse application schedules using larger palm samples to evaluate EPF efficacy against the RPW.