Hunting Billbug (Sphenophorus venatus vestitus) Response to Insecticide Application in Warm‐Season Turfgrass and Implications for Management

Hunting billbugs have recently emerged as a widespread pest of warm‐season turfgrasses. Traditional management strategies developed for other billbug species, such as the bluegrass billbug, in cool‐season turfgrass are not effective against hunting billbugs in warm‐season turfgrass. Limited field trials in warm‐season turfgrass for hunting billbug control found little to no differences among insecticides used, primarily due to insufficient billbug numbers collected. Therefore, a technique was developed using plastic containers filled with turfgrass to determine the efficacy of several insecticides on adult and larval hunting billbugs. This technique allowed for >90% of the adults and >85% of the larvae released into respective containers to be recaptured after 7 days. Products containing bifenthrin, clothianidin, cyantraniliprole, or the combination of bifenthrin + clothianidin produced 89.5, 83.3, 82.2, and 85.4% mortality in adult billbugs, respectively. Overall percent control of the larval stage was too low to develop control recommendations, where imidacloprid produced the highest mortality at 33.6%. Turfgrass managers should implement a monitoring plan to identify periods of peak adult hunting billbug activity and schedule insecticide applications during these times.