Factors influencing pesticide-biocontrol agent compatibility: A metadata-based review

The complexities of non-target effects of registered pesticides on biocontrol agents (BCAs) hinder the optimization of integrated pest management programs in agriculture. The wealth of literature on BCA-pesticide compatibility allows for the investigation of factors influencing BCA susceptibility and the generalized impacts of different pesticides. We conducted a meta-analysis using 2088 observations from 122 published articles to assess non-target effects on two phytoseiid species (Neoseiulus californicus and Phytoseiulus persimilis), a parasitoid (Encarsia formosa), and two microbial BCAs (Trichoderma harzianum and Metarhizium anisopliae). We explored the contributions of bioassay factors (exposure duration, temperature, test methods, mode of actions (MOA), and type of pesticide), and simulated effects of compatibility on target pests. MOA groups 21 and 6 were the most harmful to predatory mites and E. formosa, increasing mortality during pesticide-BCA compatibility. Exposure duration, temperature, and test methods were identified as the most influential factors increasing mortality in phytoseiids during pesticide exposure. Insecticides and fungicides were the most represented and harmful groups to BCAs. Although most bioassays were conducted at room temperature, temperatures between 21 and 22 °C were the most harmful to phytoseiids and E. formosa during toxicity assays. Exposure durations of 1-3 days (54-85 %) for predators/parasitoids and 1-5 days (>50 %) for microbial BCAs highlight the lack of data on long-term impacts. In assessing pesticide impacts on target pests, pesticides with compatible concentrations above mean LC50 values were more effective. This study not only identified compatibility trends but also highlighted factors responsible for discrepancies in results and knowledge gaps that need to be addressed.