Assumed effects of invasive intraguild predators and how to avoid the snowball effect of unsupported expectations
Abstract
The efficiency of biocontrol agents is important in determining the success of biological control. Therefore, it has been the subject of many discussions and empirical studies, which attempt to evaluate the extent to which predators are able to suppress their prey.
An interesting situation occurs when a guild of native predators is invaded by a non-native species (Rosenheim, 1993; Hentley et al., 2016). Because of strong intraguild predation, the numbers of native predators may be diminished by the invader, which lowers the biocontrol potential of the former.
But the invader also eats the shared prey, which could increase the biocontrol efficiency of the new guild. The question then is what prevails: is the final biocontrol efficiency greater or smaller after the invasion?