Optimized timing of parasitoid release: a mathematical model for biological control of Drosophila suzukii

Abstract

We present a model for the population dynamics of the invasive fruit fly Drosophila suzukii and its pupal parasitoid Trichopria drosophilae. Seasonality of the environment is captured through a system of delay differential equations with variable delays. The model is used to explore optimal timing for releasing parasitoids in biological control programs. According to the results, releasing parasitoids is most effective between late spring and early summer when the host population begins to increase. A single parasitoid release event can be more efficient than multiple releases over a prolonged period, but multiple releases are more robust to suboptimal timing choices. The findings can be useful for optimizing parasitoid release and should be

Canopy spray deposition and related mortality impacts of commonly used insecticides on Drosophila suzukii Matsumura (Diptera: Drosophilidae) populations in blueberry

“…Population modeling in pest management allows growers, researchers and practitioners to test theoretical field scenarios and management strategies against insect pests . It is acknowledged that this study does not provide empirical validation of the model outputs, but the data generated here do provide some valuable insights into promising directions for future study.…”

“…Acute mortality rates for D. suzukii adults from the laboratory mortality experiments were used in the model runs during this late‐variety blueberry cropping period. The model parameters for D. suzukii included temperature‐dependent fecundity and survival, and provided outputs for all life stages (Appendix S1). This model structure contained the refinement of D. suzukii maturation delays.…”

“…Significant progress has been made in understanding D. suzukii population dynamics, which enables us to model the response of insect populations to insecticide applications …”

“…Model outputs simulating D. suzukii population response to environmental factors, spray technologies, insecticides and biological control agents are useful to practitioners because they can simulate multiple scenarios allowing for the testing of optimal strategies. The model outputs can be used to eliminate strategies that show less promise, thereby resulting in an accelerated optimization process …”

“…21,30,31 Significant progress has been made in understanding D. suzukii population dynamics, which enables us to model the response of insect populations to insecticide applications. [32][33][34] The population density of D. suzukii is dependent on a variety of environmental and biological parameters. 32,33,35 Model outputs simulating D. suzukii population response to environmental factors, spray technologies, insecticides and biological control agents are useful to practitioners because they can simulate multiple scenarios allowing for the testing of optimal strategies.…”