Protecting Pollinators with Economically Feasible and Environmentally Friendly Ornamental Horticulture

Maintaining bee-friendly habitat and food resources in cities and suburbs can help conserve bees’ vital pollination services to cultivated ornamental plants, and to wildflowers and other native plants that support biodiversity in interspersed fragments of semi-natural habitat. This research will support guidelines to help nursery growers and landscape managers to manage insect pests without harming bees, and to ensure that plants sold in garden centers are non-hazardous to bees after being transplanted to the landscape. It also supports recommendations for woody ornamental plants that help to sustain urban bee populations. More specifically, we will assess extent and longevity of translocation of soil-applied systemic insecticides into nectar and pollen of representative woody ornamental plants following application at different times of the year to inform Best Management Practices by which producers and landscape managers can protect plants from pests without hazard to bees. Our data will help inform EPA regulatory decisions about the cost/benefit of systemic insecticides. Documenting the bee assemblages and relative attractiveness to bees of about 75 species of flowering woody ornamentals will support planting recommendations for “bee-friendly” landscapes, helping to spur consumer demand for, and sales of such plants while identifying plant species warranting particular caution when using insecticides. Finally, we will evaluate strengths and weaknesses of reduced-risk insecticides as alternatives for controlling key pests in situations where use of traditional insecticides would pose unacceptable hazard to bees.