Fungal entomopathogens: new insights on their ecology

Abstract

An important mechanism for insect pest control should be the use of fungal entomopathogens. Even though these organisms have been studied for more than 100 years, their effective use in the field remains elusive. Recently, however, it has been discovered that many of these entomopathogenic fungi play additional roles in nature.They are endophytes, antagonists of plant pathogens, associates with the rhizosphere, and possibly even plant growth promoting agents. These findings indicate that the ecological role of these fungi in the environment is not fully understood and limits our ability to employ them successfully for pest management. In this paper, we review the recently discovered roles played by many entomopathogenic fungi and propose new research strategies focused on alternate uses for these fungi. It seems likely that these agents can be used in multiple roles in protecting plants from pests and diseases and at the same time promoting plant growth.

Effects of Soil Organisms on Aboveground Plant-Insect Interactions in the Field: Patterns, Mechanisms and the Role of Methodology

“…There are various organisms, such as entomopathogens in the soil that can have direct impacts on aboveground insect performance. For instance, infection by entomopathogenic fungi, such as Beauveria bassiana and Metarhizium anisoplae can result in the quick death of many insect species (Meyling and Eilenberg, 2007;Vega et al, 2009Vega et al, , 2012, although its direct effects on aboveground insects in the field has been poorly documented. Interestingly, these fungi can also be endophytic in plants, and can influence both plant and herbivore performance (Meyling and Eilenberg, 2007;Vega et al, 2009Vega et al, , 2012Senthilraja et al, 2010;Prabhukarthikeyan et al, 2014).…”

“…For instance, infection by entomopathogenic fungi, such as Beauveria bassiana and Metarhizium anisoplae can result in the quick death of many insect species (Meyling and Eilenberg, 2007;Vega et al, 2009Vega et al, , 2012, although its direct effects on aboveground insects in the field has been poorly documented. Interestingly, these fungi can also be endophytic in plants, and can influence both plant and herbivore performance (Meyling and Eilenberg, 2007;Vega et al, 2009Vega et al, , 2012Senthilraja et al, 2010;Prabhukarthikeyan et al, 2014). Moreover, it has been shown for the fungus Metarhizium that it forms bridges between infected dead insects and plants, through which the fungus can provide the plant with extra nitrogen obtained from the insect bodies, which may also affect plant-insect interactions (Wang and St Leger, 2007;Behie et al, 2012;Sasan and Bidochka, 2012).…”

Deep space and hidden depths: understanding the evolution and ecology of fungal entomopathogens

“…However, the small subset of fungi developed as biological control agents have had limited success. Our ability to employ them effectively and reliably for pest control in the field has not matched up to expectations (Vestergaard et al 2003;Chandler et al 2008;Vega et al 2009). In part, this may be because of variable and unpredictable levels of efficacy compared to chemical pesticides (Waage 1997;Vega et al 2009), but we also lack some basic understanding of their ecology and evolution ).…”

“…Our ability to employ them effectively and reliably for pest control in the field has not matched up to expectations (Vestergaard et al 2003;Chandler et al 2008;Vega et al 2009). In part, this may be because of variable and unpredictable levels of efficacy compared to chemical pesticides (Waage 1997;Vega et al 2009), but we also lack some basic understanding of their ecology and evolution ). The importance of basic knowledge, theory and predictive ability in the use of biological control agents has been recognised for some time (Gurr et al 2000).…”

“…However, the dearth of basic information on fungal entomopathogens is pronounced even though these organisms have historically dominated the field of microbial control (Lord 2005). Vega et al (2009) have proposed the need for ''a new paradigm for fungal entomopathogens that should refocus our efforts and hopefully lead to exciting new findings.'' In this special issue of BioControl we report on some of the latest research, innovations and ideas relating to fungal entomopathogens within an ecological context.…”