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BACKGROUND: Entomopathogenic fungi can provide a set of ecological services, such as suppressing arthropod pests and plant pathogens. In this study, novel indigenous Beauveria caledonica (Bc) strains were isolated from naturally infected banana weevils (Cosmopolites sordidus) occurring in commercial banana plantations in Brazil. RESULTS: The prevalence of infection by Bc strains on field‐caught C. sordidus ranged from 1.3% to 12.9%. Similar to the Beauveria bassiana strains tested, none of the Bc strains caused more than 50% weevil mortality at a concentration of 1 × 108 conidia ml−1. Bc strain CMAA1810 caused the highest mortality in C. sordidus and had enhanced insecticidal activity when formulated with an emulsifiable oil. In paired co‐culture assays, this same strain showed a significant growth‐inhibitory effect on the causal agent of Fusarium banana wilt (Fusarium oxysporum f. sp. cubense, Foc) of twofold magnitude compared with the control. Cell‐free crude filtrates derived from the red‐pigmented culture broth of Bc (CMAA1810) strongly reduced Foc conidial viability, and this inhibitory activity was inversely related to the age of the Bc culture. Crude concentrated filtrates from 4‐day‐old cultures exhibited the strongest antifungal activity (13‐fold) compared with untreated Foc conidia. The abundant compound identified in the crude filtrate of Bc was oosporein (1,4‐dibenzoquinone) present at a concentration of 0.829 ± 0.018 mg g−1 dry matter, and the antifungal activity of the filtrate was demonstrated. CONCLUSION: These results indicated that Bc strains might have the potential to manage both C. sordidus and Foc, two of the major phytosanitary problems in banana crops worldwide. Further research under field conditions using suitable formulations of virulent Bc strains in combination with the metabolite oosporein is needed to evaluate their efficacy in the management of C. sordidus and Foc in banana plantations. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Simple Summary: Palm weevils—both South American and red palm weevils—threaten economically relevant palms, affecting oil and fruit production with a corresponding social impact. The natural tendency of the red palm weevil to explore vast territories in combination with corridors of cultivated susceptible palm species drives pest expansion in new territories. Invasion still occurs westward, from Sundaland to Portugal and the West-African coast, including the Canary Archipelago. The red palm weevil menaces the South American oil palm plantations, opening a new double-pest scenario and consequential damages or a possible coexistence with reciprocal competitive exclusion phenomena opportunities. On the brink of the red palm weevil's entrance into South America, we present available options for multiple lure-use in contaminating stations for the sustainable and effective management of both pests. Coupling several natural and synthetic lures with aggregation pheromones from the palm weevils Rhynchophorus palmarum and R. ferrugineus reveals a synergy that results in an increase in pest captures. The combined attraction of pure pheromones, ethyl acetate, and decaying sweet and starchy plant tissue increases the net total of mass-trapped weevils. The 2018 entrance of the red palm weevil (RPW) into South America has threatened palm-product income in Brazil and other neighboring countries. The presence of the new A1 quarantine pest necessitates the review of all available options for a sustainable mass-trapping, monitoring, and control strategy to ultimately target both weevils with the same device. The effective lure-blend set for the mass-trapping system will attract weevils in baiting and contaminating stations for entomopathogenic fungi that the same weevils will spread. [ABSTRACT FROM AUTHOR]