Avoidance of insect pathogenic fungi by predatory insects

Fungal entomopathogens are ubiquitous within the below- and aboveground environment and susceptible insects are predicted to be under selection pressure to detect and avoid virulent isolates. Recent evidence suggests that arthropods foraging for food and oviposition sites assess their environment for the risk of predation both to themselves and to their offspring. The detection and avoidance of entomopathogens is important for host survival, longevity and ultimately fitness; infection by an entomopathogen is often lethal to the host, thus fitness is significantly reduced. Besides studies on social insects, few studies have assessed the detection and avoidance of lethal pathogens by solitary arthropods even though pathogenic bacteria, viruses and fungi are ubiquitous worldwide and common natural enemies of many species. Here we provide an overview of the studies examining the avoidance behaviour of predatory insects in response to insect pathogenic fungi from a life history perspective. We predict that such behavioural responses are widespread and driven by the high cost of fungal infection to a host.