Finding and Studying a Natural Fungus to Control Palm Weevils

Jim Crocker
6th July, 2024

Finding and Studying a Natural Fungus to Control Palm Weevils

This study identifies the native fungal strain Beauveria bassiana Bv065 as a promising biological control agent, causing significant mortality specifically in the target pest, the palm weevil (Dynamis borassi, pictured).

Photo adapted from: Douglas / CC BY (Source)

Key Findings

  • The study focused on a native strain of the fungus Beauveria bassiana (Bv065) from southwestern Colombia to control the palm weevil Dynamis borassi
  • Bv065 thrives best at temperatures between 25-30°C and pH levels of 6-9, which are optimal for its growth
  • Bv065 caused significant mortality in D. borassi within nine days, but was less effective against another palm weevil, Rhynchophorus palmarum
The research conducted by Agrosavia aimed to isolate and characterize a native strain of the fungus Beauveria bassiana, coded as Bv065, to explore its potential as a biological control agent against the palm weevil Dynamis borassi[1]. This study is significant as it provides an eco-friendly alternative to conventional insecticides, particularly for controlling palm weevil infestations in neotropical regions, such as coconut and peach palm cultivation. Beauveria bassiana is an entomopathogenic fungus, meaning it can infect and kill insects. The strain Bv065 was isolated from a naturally infected D. borassi specimen collected in southwestern Colombia. Molecular identification confirmed that Bv065 is indeed B. bassiana, showing high sequence similarity with known reference strains. This identification is crucial as it ensures the reliability and effectiveness of the strain in biological control applications. The physiological characterization of Bv065 revealed that it thrives best at temperatures between 25 to 30°C and pH levels ranging from 6 to 9. Additionally, metabolic profiling identified key carbon sources that support optimal growth of the strain, including sucrose, D-mannose, and γ-amino-butyric acid. Understanding these optimal growth conditions and metabolic preferences is essential for scaling up production and formulating effective biopesticides. Enzymatic analyses showed that Bv065 exhibits robust protease activity. Proteases are enzymes that break down proteins, and in this context, they play a crucial role in degrading the insect cuticle (the outer shell of insects) and facilitating the fungus's penetration into the host. This enzymatic activity underscores the entomopathogenic potential of Bv065, making it a promising candidate for biocontrol. The pathogenicity of Bv065 was evaluated against D. borassi, where it caused significant mortality within nine days of exposure. However, the strain showed limited effectiveness against another palm weevil, Rhynchophorus palmarum. This specificity suggests that Bv065 could be particularly useful for targeted pest management in regions where D. borassi is a primary concern. Previous studies have also highlighted the potential of Beauveria bassiana strains in biological control. For instance, native endophytic strains of B. bassiana were shown to have a biocontrol effect on whiteflies and promote tomato growth[2]. Similarly, Brazilian isolates of B. bassiana demonstrated high pathogenicity against Rhynchophorus palmarum, with mortality rates between 90 and 100%[3]. Another study developed a Beauveria bassiana-based attract and infect device (AID) to control Rhynchophorus ferrugineus, showing significant efficacy in field trials[4]. The findings from Agrosavia's study align with these previous results, reinforcing the potential of B. bassiana as a versatile biocontrol agent. However, the specific focus on D. borassi and the detailed characterization of Bv065 add new insights, particularly for integrated pest management strategies in neotropical regions. Future research should focus on refining mass production methodologies and formulating novel delivery systems for Bv065. Comprehensive field efficacy trials are also necessary to fully unlock the potential of this strain in sustainable pest management practices. By advancing our understanding of entomopathogenic fungi like B. bassiana, we can develop more effective and eco-friendly alternatives to conventional insecticides, contributing to the broader goal of sustainable agriculture.

AgricultureBiotechMycology

References

Main Study

1) Isolation and characterization of a native strain of the entomopathogenic fungus Beauveria bassiana for the control of the palm weevil Dynamis borassi (Coleoptera: Curculionidae) in the neotropics

Published 5th July, 2024

https://doi.org/10.1007/s11274-024-04044-5

Related Studies

2) Beauveria bassiana Multifunction as an Endophyte: Growth Promotion and Biologic Control of Trialeurodes vaporariorum, (Westwood) (Hemiptera: Aleyrodidae) in Tomato.

https://doi.org/10.3390/insects11090591

3) Native Entomopathogenic Fungi Isolated from Rhynchophorus palmarum (Linnaeus, 1758) in Northeast Brazil.

https://doi.org/10.3390/insects15030159

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

https://doi.org/10.1002/ps.4888


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