Root weevils are destructive pests of many plants including strawberries, raspberries, rhododendrons, euonymus, and azaleas. The young larvae feed on the roots, while the black, snouted, weevil adults emerge from the soil at night to feed on the leaves. They create a distinct notching in the leaves.
The common control for these pests is drenching the soil with an insecticide. However, recent research from Agri-Food Canada in British Columbia has uncovered a potentially safer control: aluminum flashing.
Researchers laid a barrier of 12-inch-wide aluminum flashing in the ground around plants and beds. One-third of the flashing was buried underground, and a strip of slick Teflon tape was placed along the top to prevent the root weevils from climbing over the flashing. The aluminum flashing excluded up to 84 percent of the weevils from the control plots. A bonus of this barrier method is it didn't exclude small beneficial ground beetles.
For more information on this research, go to: Environmental Entomology.