Mycoinsecticides...as nature intended?

Entomopathogenic fungi (EPF) such as Metarhizium and Beauveria species are often amenable to being developed as biological insecticides. This is largely due to the ease with which they can be mass produced, relative, for example to species of Entomophthorales, which are often considered appropriate for conservation approaches. This division of roles self-selects for characteristics, such as ease of mass production, virulence and speed of action with Metarhizium and Beauveria, which may not be the most suitable characteristics for sustainable pest management and are certainly not those that occur most in natural eco-systems. Rather than focus on an atypical mode of action, perhaps exploitation of the natural characteristics of EPF will allow more effective use. It will lead to more relevant research areas than focussed on at present.

The modes of action of EPF are quite varied and more activities will be understood in the future. This diversity of activities regularly results in good regulation of insect populations – outbreaks are the exception rather than the rule. Mycoinsecticide research often focuses on marked specificity and rapidity in reaching high levels of kill, but only exceptionally is rapid action truly necessary. A complex of natural enemies, including predators and parasitoids (even if most are operating at low levels of activity), may lead to greater stability within agro-ecosystems. This in turn may result in fewer control interventions. Some bizarre suggestions about EPF in agro-ecosystems will not be as bizarre as some of their true activities in nature.