The annual bluegrass weevil, Listronotus maculicollis (Kirby), is a highly destructive pest of golf course turfgrass in eastern North America. Previous research has demonstrated that females prefer to oviposit within short-mown turfgrasses (<1.25 cm), and these offspring have improved fitness traits compared with larvae developing in higher-mowed turf. However, damage to putting green turf (<3.55 mm) is rarely reported. We investigated whether this phenomenon was due to adult removal through mowing or an inability of larvae to develop within a shortened plant. Greenhouse studies revealed that between 26% and 38% of adults were removed when turf was mowed at 2.54 mm (0.100 in), but the effect diminished with increasing mowing heights. The majority of adults survived mowing, indicating a potential for adults to reinvade turf stands adjacent to areas where grass clippings are discarded. Females oviposited in all mowing height treatments in laboratory and field experiments. However, behavior was influenced by plant height, as significantly fewer eggs were placed inside of the turfgrass stem at the lowest mowing height. Larval development was not affected by egg placement or turf height, and significant numbers of larvae were capable of developing to damaging stages (fourth- and fifth-instar larvae) in all treatments. Our findings suggest that L. maculicollis poses a threat to putting green-height turf, but the probability of damage occurring and need for insecticide applications may be lessened on low-mown surfaces. Future studies are needed to determine factors that influence L. maculicollis movement within the turfgrass canopy to optimize mechanical control.

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The annual bluegrass weevil (Listronotus maculicollis), is the most destructive insect pest of fine turf found on golf courses in eastern North America. Although considerable densities of adults may be found on putting greens in spring following emergence from overwintering, larval damage in these areas is rare. Annual bluegrass (Poa annua L.) putting surfaces are frequently treated with nitrogen and plant growth regulators during this time. We assessed whether these inputs alone and in combination influenced L. maculicollis oviposition site selection, larval fitness, or survival. Significantly more females were found in high-nitrogen (39 kg N ha -1 mo -1 ) treatments in laboratory preference assays, though significantly more eggs were found in the moderate concentration treatments (19.5 kg N ha -1 mo -1 ). Choice and no-choice assays demonstrated an ovipositional preference for the moderate nitrogen rate as well, though no fitness advantage was observed. Given that most P. annua greens management programs include plant growth regulation, field experiments were conducted to assess ovipositional preference in P annua treated with various nitrogen concentrations (4.88, 19.5 and 39 kg N ha -1 mo -1 ) in combination with a gibberellic acid inhibitor (trinexapac-ethyl) and/or a seedhead suppressor (ethephon). Significantly fewer larvae were found in trinexapac-ethyl treatments in two of the three years of study, with significantly higher counts in the other year. No differences were detected in larval survival or fitness related to nitrogen in any year. Taken together, these findings suggest that fertility regimes are not likely to influence L. maculicollis development, though further studies are needed to assess the effects of trinexapacethyl.