Insect Pathogenic Fungi for Biocontrol of Plague Vector Fleas: A Review

Abstract

Bubonic plague is a lethal bacterial disease of great historical importance. The plague organism, Yersinia pestis, is primarily transmitted by fleas (Siphonaptera). In natural settings, where its range expands, Y. pestis resides in association with wild rodents and their fleas (sylvatic plague). While chemical insecticides are used against plague vector fleas, biological approaches have not been as critically evaluated. Benign and cost-effective control methods are sorely needed, particularly where imperiled species are at risk. Here we explore the potential of two representative insect pathogenic fungi, Beauveria bassiana Vuillemin 1912 (Hypocreales: Cordycipitaceae) and Metarhizium anisopliae Metschnikoff 1879 (Hypocreales: Clavicipitaceae), each already used commercially worldwide in large-scale agricultural applications, as candidate biopesticides for application against fleas. We review the life cycles, flea virulence, commercial production, and field application of these fungi, and ecological and safety considerations. Pathogenic fungi infections among natural flea populations suggest that conditions within at least some rodent burrows are favorable, and laboratory studies demonstrate lethality of these fungi to at least some representative flea species. Continued study and advancements with these fungi, under appropriate safety measures, may allow for effective biocontrol of plague vector fleas to protect imperiled species, decrease plague outbreaks in key rodent species, and limit plague in humans.

Human Flea Pulex irritans Linnaeus, 1758 (Insecta: Siphonaptera: Pulicidae)

“…These authors suggest that residual spraying of insecticides using pyrethroids or insect growth regulators may be useful; however, insecticide resistance in fleas is widespread (Rust 2016). There are some reports of potential flea biocontrol strategies using pathogenic fungi (e.g., Beauveria bassiana) that have shown promise (Eads et al 2021). Also, certain nematode species (e.g., Steinernema feltiae) have shown success at flea control (Samish et al 2020).…”

Biocontrol of Pathogens using a Sustainable Tool: Opportunities and Challenges

“…Saha et al (14) proposes a model to examine the impact of wild plant species on biologically based pest control strategies. Eads et al (15) discusses the fungi's life cycles, flea virulence, commercial production, field use, ecological and safety factors, as well as their production and field use. Bamisile et al (16) suggests that fungal endophytes might be used as an alternative to inorganic fertilizers to benefit crops.…”

Acute Oral Toxicity of two Products from a Microbial Pest Control Agent (Beauveria bassiana) on Physiological Status Aspects of Male Albino Rats

“…More than 1000 species of entomopathogenic fungi (EPF) from 85 genera have been found to infect pests in agricultural, veterinary, and medical pests [5] . In the Hyphomycetes class, about 100 mycoinsecticides are commercially registered worldwide and among them, Beauveria bassiana (Balsamo-Crivelli) Vuillemin, a cosmopolitan anamorphic genus of soilborne necrotrophic entomopathogenic fungi, is one of the most useful fungi, based-mycopesticides [6] .…”