Revisiting implementation of multiple natural enemies in pest management

Area of Science:

• Ecology
• Evolutionary Biology
• Epidemiology

Background:

• Biological control aims to reduce pests using natural enemies, with multi-enemy strategies showing promise.
• Theoretical studies on co-infections exist, but modeling multi-enemy biological control outcomes is underexplored.

Purpose of the Study:

• To theoretically investigate how the number of natural enemies impacts biological control efficiency.
• To model the outcomes of using multiple parasite species against a target pest.

Main Methods:

• Eco-epidemiological modeling combined with Adaptive Dynamics game theory.
• Analysis of how parasite species addition affects virulence and pest mortality.

Main Results:

• Increasing parasite species enhances evolutionarily stable virulence and pest mortality.
• Multi-enemy control may have marginal benefits or be counterproductive with excessive numbers.
• Potential for evolutionary suicide (parasite extinction) and coexistence at the edge of extinction observed.

Conclusions:

• While multiple parasites can increase pest mortality, optimal numbers are crucial for effective biological control.
• Excessive enemy assemblages can lead to negative outcomes, including parasite extinction.
• The study highlights complex evolutionary dynamics in multi-enemy biological control systems.