Location: Southern Insect Management Research
Project Number: 6066-22000-091-017-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 30, 2024
End Date: Jul 31, 2028
Objective:
Determine insecticide resistance in different insect pests infesting row crops such as soybeans and corn in the field as well as storage environments in the Mid-Southern region.
Approach:
This project has two primary components: first field sampling and population dynamics and second, laboratory bioassays to examine insecticide resistance and the underlying mechanisms. To assess the population dynamics of stink bugs and other insect pests, multiple samples will be collected from various growing locations. These samples will then be analyzed in laboratory trials to monitor pesticide resistance. The findings from these studies will help refine pest management recommendations and inform the selection of insecticides. Additionally, different insecticide products will be evaluated for their economic and sustainable control of stink bug populations in multiple replicated field trials. Stink bug abundance will be measured before and after insecticide treatments in research plots, and the relative effectiveness of the insecticide treatments will be determined.
In the laboratory bioassays, commercially formulated pesticides that are commonly used by growers in this region will be evaluated and examined for the insecticide resistance development in different populations of stink bugs species complex as well as various pests that infest row crops in the on-farm storage environment. The pesticides will be diluted to the desired concentrations using distilled water. The range of pesticide concentrations will be selected based on previous studies and recommended rates. For each pesticide, at least five treatment concentrations will be tested to generate concentration-mortality curves and calculate LC50 values with 95% confidence intervals. Distilled water will serve as the negative control. Each pesticide concentration will be replicated three times by spraying 1 mL of the solution onto 10 insects using a customized spray chamber, where the test insects will be placed inside a clear 473-mL plastic container with the customized mesh lid removed during spraying. For data collection and analysis, treated stink bugs will be observed for mortality rates at 24 and 48 hours after treatment (HAT). Mortality will be defined as the absence of movement for a continuous 30-second period. The concentration-mortality data at 24 HAT will then be analyzed using POLO Plus 2.0 to estimate the 50% lethal concentrations (LC50) with 95% confidence intervals.
