Ecosystem services provided by soils can be altered when insecticides come into contact with the soil and negatively affect beneficial soil organisms. Soil microarthropods and microbes are major components of soil biodiversity and help maintain healthy soils with diverse biological functions and contribute to ecosystem services such as carbon cycling and fertility. A relatively low cost neonicotinoid insecticide, imidacloprid, is used on many crops as well as managed turfgrass to control many economically damaging arthropod pests. To quantify the impacts of imidacloprid on soil microarthropod biodiversity and microarthropod-driven ecosystem services, we conducted a field and laboratory experiment in turfgrass. We hypothesized that a decrease in microarthropod abundance due to imidacloprid will lead to reduced microbial biomass and activity. We grew tall fescue (Festuca arundinacea) in control plots and in imidacloprid-treated plots. Soil microarthropod abundance and soil microbial biomass and function were assessed from soil samples collected 1, 2, 4, and 6 weeks after planting. In a concurrent lab study, we grew tall fescue in pots in growth chambers with Folsomia candida, where half of the pots received an imidacloprid soil drench. Soil microbial functional responses were measured and soils were also incubated to assess microbial carbon and nitrogen mineralization.
Results/Conclusions
Preliminary results from a study conducted in the summer of 2015 where we applied imidacloprid to turfgrass plots located on golf courses in Central New York showed that one application of imidacloprid reduced the abundance of soil microarthropods.