Optimizing Sampling Technique Parameters for Increased Precision and Practicality in Annual Bluegrass Weevil Population Monitoring

SIMPLE SUMMARY: The annual bluegrass weevil (ABW) is the most severe insect pest of short-mown turfgrass in eastern North America, and the proper monitoring of overwintered adult populations in spring is critical to the timely management of this significant pest. We evaluated three sampling methods including soap flushing, vacuuming, and mowing in golf course putting greens and fairways for monitoring ABW adults. Soap flushing was the most efficient method, and adult extraction efficiency was not affected by the temperature or time of day; both vacuuming and mowing were more efficient for adult recovery on greens vs. fairways; the efficiency of mowing was affected by the time of day and temperature, but vacuuming efficiency was not. Hence, soap flushing was determined to be the optimal method for monitoring adult ABWs, while vacuuming may serve as an alternative sampling method on greens. ABSTRACT: The annual bluegrass weevil (ABW), Listronotus maculicollis (Kirby), a significant pest of short-mown turfgrass in eastern North America, has developed widespread insecticide resistance because of excessive synthetic insecticide use. The proper monitoring of this pest may reduce insecticide applications in time and space. This study evaluated three sampling methods (soap flushing, vacuuming, and mowing) in golf course greens and fairways for monitoring adult ABW. Soap flushing was the most efficient method, especially with an 0.8% solution in two portions of 500 mL, extracting over 75% of the adults, and the extraction efficiency was not affected by the temperature or time of day. Vacuuming was more effective for recovering adult ABWs on greens (4–29% extracted) than on fairways (2–4%) but was not affected by the time of day. The extraction of adult ABWs in mower clippings was significantly affected by mowing height (higher recovery from greens versus fairways), and the efficiency decreased with the temperature. Adding a brush to the mower increased adult removal (from 15% to 24%) in greens at higher temperatures (18–25 °C); 70% of adults recovered in the clippings were unharmed. Overall, our findings suggest that soap flushing should be the preferred method for monitoring adult ABWs, and vacuuming might be a viable alternative for greens.