Annual bluegrass weevil IPM: plant resistance/tolerance and semiochemicals for moniroting and management

The annual bluegrass weevil (ABW), Listronotus maculicollis Kirby (Coleoptera: Curculionidae) is a severe pest of golf courses throughout the Northeast. Because of insecticide overuse and the resulting development of resistance, ABW management can no longer rely solely on chemical control. Host plant resistance/tolerance and practical and reliable monitoring tools are cornerstones of sustainable pest management program. The susceptibility of three bentgrass species (seven cultivars) to ABW in comparison with annual bluegrass was investigated in choice and no-choice laboratory oviposition experiments and greenhouse larval survival experiments. ABW females laid significantly more eggs in Poa annua (28 ± 5 eggs per plug) than in any bentgrass species/cultivars (up to 8 eggs per plug) inif no choice experiments. In choice experiments, females preferred Poa annua for oviposition in choice experiments (on average 88% of all laid eggs) over bentgrasses. Although no distinct preferences for oviposition were observed among bentgrass species/cultivars, females tended to lay more eggs in ‘Penncross’, ‘L-93’ cvs. (creeping bentgrass) and ‘Capri’ cv. (colonial bentgrass). Adult ABWs fed equally on all grass species tested. Y-tube olfactometer assays were conducted to determine behavioral responses of males and females to host plant volatiles and possible pheromones. Females were strongly attracted to Poa annua plants, which suggests that plant volatiles may be important in host-finding, and need to be further investigated as potential attractants as monitoring and/or management tools.