Predicting predation efficiency of biocontrol agents: linking behavior of individuals and population dynamics

Behavioral ecology and population ecology are two separate branches of ecology; studies linkingthe effect of individual behavior and population dynamics are rare. This paper connects a stochastic optimalforaging model of insect predators with an age structured population model of its prey. I modeled syrphidlarvae feeding on cereal aphids, an interaction critical to cereal crops in Germany. The key stochastic elementin this model is the foraging success of predators, which influences survival and developmental time ofpredators and mortality of the prey population. The model predicts that the level of control incurred bypredators is highest if predators arrive when prey numbers are still small, the growth rate of prey population issmall, and predator density is moderately high. If the number of predators per prey was high or preydistribution was much aggregated, predators were less successful in finding prey. As a result predationefficacy was reduced.