Turfgrass is an important cropping system covering >16 million hectares in the United States. Synthetic insecticides, which are important tools in managing several key insect pests in these landscapes, have been implicated in the decline of managed and wild pollinators. The public perception linking the use of chemical insecticides to pollinator population declines threatens their future use and our ability to maintain functional and aesthetically acceptable landscapes. Extension and research entomologists from across the United States met in 2016 for the “Summit for Protecting Pollinators in Turf” to review the scientific literature on nontarget impacts of pest management practices on pollinators in turfgrass landscapes, to develop best management practices for protecting these organisms, and to identify knowledge gaps and prioritize future research needs. The group identified that there is a scarcity of detailed research on pollinator health in turf landscapes and has prioritized areas where research was most needed to conserve pollinator populations while balancing the needs for maintaining healthy turfgrass.

The annual bluegrass weevil, Listronotus maculicollis Kirby, is the most difficult to control insect pest of short-mown golf course turf in the northeastern United States and Eastern Canada. We conducted a survey among golf course superintendents throughout the weevil's area of impact to better understand the severity of damage, prevalence of insecticide resistance, information sources, and trends in management practices. Responses were received from 293 golf courses in 14 U.S. states and 2 Canadian provinces. The average population caused damage to 6.6 fairways, 5.7 tee boxes, and 6.4 greens/collars, amounting to a total of 5.2 ha requiring protection on an 18-hole facility. On average, courses made 3.9 insecticide applications per year and spent US$9,270 on L. maculicollis management. Twenty percent of the responders reported having a pyrethroid-resistant L. maculicollis population. “Resistant” populations were located across the region, though higher-than-average incidence was reported from areas with long histories of managing L. maculicollis. “Resistant” populations caused more damage than “susceptible” populations, reported higher average insecticide budgets, and were more likely to make more than five insecticide applications per year than “susceptible” courses. Surveys indicated that, despite the reliance on chemical controls, 90% of turf managers used multiple monitoring tactics to better time and target controls. The greatest influence on management philosophy was by University personnel (43%) followed by colleagues (31%) and sales/distributors (21%). This survey highlights the need for developing alternatives to chemical insecticides to control L. maculicollis and provides insight into the costs associated with the development of pyrethroid resistance.

Listronotus maculicollis Kirby is a highly destructive pest of low mown, cool-season turfgrasses in the northeastern United States and Canada. Behavi

Easy handling and low unit N cost make prilled urea (46-0-0) a popular fertilizer. While incomplete recovery of granular urea applications by turfgrass is documented, field evaluations of NH₃ volatilization mitigation by coatings or bioinhibitor efficiency enhancements are limited. Meanwhile, NH₃ emissions reduce air quality and contribute to nutrient loading of water resources. Our objectives were to quantify 3- and 6-d ammonia emission and 9-week turfgrass recovery of unincorporated granular fertilizer application to turfgrass. In 2014 and 2015, commercial urea-N fertilizers were broadcast over a mature Kentucky bluegrass (Poa pratensis L. ‘Midnight’) lawn at 43 kg ha⁻¹. Treatments included conventional urea and three enhanced-efficiency fertilizers; a blended fertilizer with 25% of its urea-N supplanted by polymer- and polymer-/sulfur-coated prills, or two stabilized urea fertilizers both amended by N-(n-butyl) thiophosphoric triamide (NBPT) and dicyandiamide (DCD) inhibitors. Using a 51% ‘trapping-efficiency’ flux chamber system under the field conditions described, 23.1 or 33.5% of the conventional urea-N was lost as NH₃ over the respective 3- or 6-d period following application. Alternatively, dual amendment by NBPT and DCD resulted in approximately 10.3 or 19.6% NH₃-N loss over the respective 3- or 6-d periods, and greater fertilizer-N recovery by the turfgrass over the 9-week experiments.

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.