Author
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Bruck, Denny |
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Submitted to: BioControl
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/28/2009 Publication Date: 10/24/2009 Citation: Bruck, D.J. 2009. Fungal entomopathogens in the rhizosphere. Biocontrol. 55(2):416-422. Interpretive Summary: The insect-killing fungi, Beauveria bassiana and Metarhizium anisopliae have been used for the biological control of a wide array of foliar and soil-borne insect pests. Most studies have focused on the use of these fungi as “plug in” replacements for chemical insecticides with little consideration of the biological niche that the fungi are adapted for in the environment. The biology of fungal pathogens used for insect control, particularly in the soil environment, is an understudied area of insect pathology. The rhizosphere is the first few millimeters of soil surrounding actively growing plant roots. Because of root exudates released by the plant, the rhizosphere is an environment rich with microorganisms. The study of the biology of insect-killing fungi, particularly in the rhizosphere is gaining momentum as scientists realize the critical role that a more thorough understanding of fungal biology has on the efficacy of the use of fungi in microbial control. While our understanding of the biology and significance of insect-killing fungi in the rhizosphere is just beginning to take shape, it is clear that an increased understanding of the relationship between these fungi and their plant host is a key component in the development of successful microbial control of soil-borne insect pests. The objective of this review is to bring together the relatively scant data available to date on the subject and highlight the tremendous importance that these findings have had in opening our eyes to the importance of this area of study. Technical Abstract: Entomopathogenic fungi are found in a wide variety of fungal groups from water molds to basidiomycetes, yet there are a number of fungal groups with no entomopathogenic representative. The order Hypocreales contains the largest number of entomogenous fungi including two of the most widely studied, Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) and Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae). Most studies have focused on the use of these fungi as “plug in” replacements for chemical insecticides with little consideration of the biological niche that the fungi are adapted for in the environment. The biology of fungal pathogens used for insect control, particularly in the soil environment, is an understudied area of insect pathology. The rhizosphere is the region of soil in which the release of root exudates influences the soil microbiota. The study of the biology of entomopathogenic fungi, particularly in the rhizosphere, is gaining momentum as scientists realize the critical role that a more thorough understanding of fungal biology has on the efficacy of these fungi in microbial control. While our understanding of the biology and significance of entomopathogenic fungi in the rhizosphere is just beginning to take shape, it is clear that an increased understanding of this relationship is a key component in the development of successful microbial control of soil-borne insect pests. The objective of this review is to bring together the relatively scant data available to date on the subject and highlight the tremendous importance that these finding have had in opening our eyes to the importance of this area of study. |
