Revisiting implementation of multiple natural enemies in pest management

Abstract

A major goal of biological control is the reduction and/or eradication of pests using various natural enemies, in particular, via deliberate infection of the target species by parasites. To enhance the biological control, a promising strategy seems to implement a multi-enemy assemblage rather than a single control agent. Although a large body of theoretical studies exists on co-infections in epidemiology and ecology, there is still a big gap in modelling outcomes of multi-enemy biological control. Here we theoretically investigate how the efficiency of biological control of a pest depends on the number of natural enemies used. We implement a combination of eco-epidemiological modelling and the Adaptive Dynamics game theory framework. We found that a progressive addition of parasite species increases the evolutionarily stable virulence of each parasite, and thus enhances the mortality of the target pest. However, using multiple enemies may have only a marginal effect on the success of biological control, or can even be counter-productive when the number of enemies is excessive. We found the possibility of evolutionary suicide, where one or several parasite species go extinct over the course of evolution. Finally, we demonstrate an interesting scenario of coexistence of multiple parasites at the edge of extinction.

Benefiting from Complexity: Exploring Enhanced Biological Control Effectiveness via the Simultaneous Use of Various Methods for Combating Pest Pressure in Agriculture

“…There are not many extant studies that have explored this concept in the past, possibly because they are difficult to conduct due to many influencing factors [10]. Some of the studies write about the use of mixed species cover crops [11], others about the use of two different biological control agents (BCAs) concurrently [12][13][14][15][16], or just one BCA concurrently with different inert dusts in storage facilities [17][18][19]. Most studies found that a combined approach improves the effectiveness of pest control, while some report otherwise, indicating that this area of research is complex and there are many environmental and other factors contributing to the effectiveness of these approaches.…”

Unlocking Synergistic Potentials: Exploring Enhanced Biological Control Efficacy Through Simultaneous Use of Various Methods for Combating Pest Pressure in Agriculture

“…There are not many extant studies that have explored this concept in the past, possibly because they are difficult to conduct with many influencing factors [10]. Some of the studies write about the use of mixed species cover-crops [11], others about the use of two different biological control agents (BCAs) concurrently [12][13][14][15][16], or just one BCA concurrently with different inert dusts in storage facilities [17][18][19]. Most studies found that a combined approach improves the effectiveness of pest control, while some report otherwise, indicating that this area of research is complex and there are many environmental and other factors contributing to the effectiveness of these approaches.…”