Evaluation of Insecticides for Lethal Dose, Lethal Concentration, and Field Activity on Hunting Billbug in Warm-Season Turfgrass

The response of hunting billbug, Sphenophorus venatus vestitus Chittenden (Coleoptera: Curculionidae), to insecticides was evaluated in field and laboratory bioassays. Field bioassays evaluated treatment by timing and compound. Laboratory bioassays evaluated lethal dose and lethal concentration. A field evaluation of a bifenthrin and imidacloprid combination (Allectus) suggests that it is effective at reducing adult billbug populations in North Carolina when applied in September and May/September. LD₉₅ and LC₉₅ data collected in the laboratory showed significant differences between lethal doses of neonicotinoids and pyrethroids or combination products which contain pyrethroids. Pyrethroid-containing products required lower concentrations to achieve mortality than neonicotinoids alone.