Efficacy of Entomopathogenic Fungi Against Bruchus rufimanus (Coleoptera: Chrysomelidae) in Laboratory and Field Trials Using Dropleg Spraying Technique

Adrien Rodrigue Lugendo, Ibtissem Ben Fekih, Rudy Caparros Megido, Jérôme Pierreux, Frédéric Francis and Arnaud Segers ()
Additional contact information
Adrien Rodrigue Lugendo: Functional and Evolutionary Entomology, University of Liège—Gembloux Agro-Bio Tech, Passage des Déportés, 2, 5030 Gembloux, Belgium
Ibtissem Ben Fekih: Functional and Evolutionary Entomology, University of Liège—Gembloux Agro-Bio Tech, Passage des Déportés, 2, 5030 Gembloux, Belgium
Rudy Caparros Megido: Functional and Evolutionary Entomology, University of Liège—Gembloux Agro-Bio Tech, Passage des Déportés, 2, 5030 Gembloux, Belgium
Jérôme Pierreux: Functional and Evolutionary Entomology, University of Liège—Gembloux Agro-Bio Tech, Passage des Déportés, 2, 5030 Gembloux, Belgium
Frédéric Francis: Functional and Evolutionary Entomology, University of Liège—Gembloux Agro-Bio Tech, Passage des Déportés, 2, 5030 Gembloux, Belgium
Arnaud Segers: Functional and Evolutionary Entomology, University of Liège—Gembloux Agro-Bio Tech, Passage des Déportés, 2, 5030 Gembloux, Belgium

Agriculture, 2025, vol. 15, issue 4, 1-18

Abstract: Entomopathogenic fungi (EPF)-based biopesticides have attracted growing interest in pest management as alternatives to neurotoxic insecticides. Their potential was evaluated against various pests, including the broad bean weevil ( Bruchus rufimanus Boheman 1833 ), a significant threat to faba bean ( Vicia faba L.) crops. This study examined the entomotoxic effects and sublethal impacts (on oviposition) of three fungal strains under laboratory conditions: Beauveria bassiana (GHA), Metarhizium brunneum (USDA 4556), and M. brunneum (V275) on B. rufimanus adults. Subsequently, a large-scale field trial assessed the efficacy of B. bassiana (GHA) against B. rufimanus infestations using conventional anti-drift and dropleg spraying methods. The laboratory LT 50 values ranged from four days for B. bassiana to eight days for M. brunneum (V275). The mortality rates recorded after ten days ranged from 86.6% for M. brunneum (V275) to 96.6% for B. bassiana (GHA). The inhibition of oviposition rates ranged from 12% for M. brunneum (USDA 4556) to 36% for B. bassiana (GHA). Field trials showed that the dropleg nozzles targeted faba bean pods, the oviposition sites of B. rufimanus , more effectively than the anti-drift nozzles. However, both fungal and chemical treatments applied via dropleg nozzles offered limited protection, reducing the infestation rates by 7% and 14%, respectively, with only a 3% improvement over anti-drift nozzles. This suggests that the large-scale spraying of chemical or fungal agents, including B. bassiana GHA, is not an optimal IPM strategy for managing B. rufimanus in faba beans. These laboratory and field results highlight the potential of EPF for managing B. rufimanus . However, the limitations of spray-applied plant protection methods underscore the need to redirect research toward more targeted strategies, such as attract-and-infect or endophytic EPF approaches.

Keywords: Vicia faba; faba bean; biopesticide; microbial control; Beauveria bassiana; Metarhizium brunneum (search for similar items in EconPapers)
JEL-codes: Q1 Q10 Q11 Q12 Q13 Q14 Q15 Q16 Q17 Q18 (search for similar items in EconPapers)
Date: 2025
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2077-0472/15/4/376/pdf (application/pdf)
https://www.mdpi.com/2077-0472/15/4/376/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jagris:v:15:y:2025:i:4:p:376-:d:1588509

Access Statistics for this article

Agriculture is currently edited by Ms. Leda Xuan

More articles in Agriculture from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().