The implementation of an integrated pest management (IPM) program is the best way to keep tree diseases and insects under control. This plan hinges on the idea that in an ecosystem, a certain level of insects and disease is naturally present and that the chemical eradication of these organisms may disrupt a delicate balance in nature. The plan calls for the establishment of damage/economic thresholds to determine at what point chemical application of pesticides is warranted, and ensures that the purpose of this chemical application is only to keep pest populations within these thresholds.
There are many different components to an I.P.M. system. Scouting for the early identification of plant problems, cultural practices that increase tree vigor, selection of species resistant to pest problems, and the use of biological controls all play a role in reducing chemical pesticide applications and lead to a healthy urban forest.
The following pages provide specific detail on two particular areas of concern to the Forestry Division: