Timing Controls for Insect Pests of Woody Ornamentals
Turfgrass represents a relatively uniform monoculture in the landscape when compared to ornamental trees and shrubs. Currently, IPM for woody ornamentals relies heavily on cultural and pesticide treatments, despite increasing interest in the development and utilization of biological control strategies. Considerable effort has been expended on developing control strategies for the black vine weevil. Insecticides applied to the soil are popular with many nurserymen and landscape maintenance contractors because of the high level of control that was achieved with chlorinated hydrocarbon insecticides during the 1960s and 1970s. In contrast to insecticides, nematodes are targeted at larvae and show promise as biological control agents for this insect. Foliar insecticide applications are effective against rhododendron gall midge during the first growth flush when midge emergence and oviposition is restricted to a relatively short period of time. Fletcher scale Parthenolecanium fletcheri (Cockerell) is a serious pest of Taxus spp. and an occasional pest of arborvitae (Thuja spp.).