Geraniums could hold key to controlling Japanese beetles

Japanese beetle (Popillia japonica) feeds on nearly 300 plant species in almost 80 plant families. It is considered to be the most destructive pest of ornamental and turf plants in the eastern United States, with more than $450 million spent each year to control it and replace damaged plants.
Geranium (Pelargonium zonale) is one plant whose flowers can be deadly to beetles. Within 30 minutes of consuming the petals, the beetle rolls over on its back and it remains paralyzed for several hours. Under laboratory conditions, the beetles typically recover within 24 hours, but under field conditions they often die because predators devour them.
USDA-Agricultural Research Service scientists are working on a natural, botanical formulation for beetle control based on the paralyzing compounds isolated from geraniums. Scientists are also studying the differences in the leaf surfaces of geraniums to determine ways to help leaves retain pesticides that are applied to them, which could help to reduce pesticide use.