Users of this guide are urged to recognize that the management of insect and mite pests of trees and shrubs can, at times, be incredibly complicated. As landscape practitioners, often managing pest populations below levels that are damaging to the overall health of the host plant is our primary goal.
Completely eradicating a pest population is often not practical, too expensive, or unnecessary with a few notable exceptions. On average on ornamental woody plants, managing the overall health of the plant should be the main goal.
It is highly recommended that preventative plant health care options be the priority when managing insect pests. Often, preventing and reducing host plant stress can vastly reduce the effects of pest pressure and thus reduce dependency on insecticides and other pesticides.
Users of this Guide are encouraged to prevent pest insect pressure by: selecting the right plant for the right location, follow proper planting and installation best practices, reduce abiotic or other biotic stressors through proper plant maintenance, avoid unnecessary injury to trees and shrubs (which is often attractive to secondary insect invaders), and avoid planting trees or shrubs with a known significantly damaging insect pest (such as invasive insects lethal to the tree currently in a regional or national outbreak).
UMass Extension works to educate practitioners on responsible pest management within an Integrated Pest Management (IPM) framework. This is a holistic, science-based approach to pest management. Practicing IPM means combining a wide array of available tools for pest management to reduce costs and dependency on pesticides, as well as potential for risks to people and the environment. For more information about Integrated Pest Management, visit: https://ag.umass.edu/integrated-pest-management/about .
An important part of IPM is learning about, recognizing, and conserving beneficial insects and natural enemies. The vast majority of insects on planet earth are not pests, and many of them provide crucial ecosystem services including but not limited to: pollination, decomposition, predation and parasitism of pest insect populations, and act as food for other non-insect wildlife.
Land management practices that promote insect populations, where and whenever possible, are highly encouraged. For example, if a species of insect discussed within this Guide is noted as producing only aesthetic damage to its host plants (not damage to the overall health of the tree or shrub) it should be tolerated.
Another important part of IPM includes, when chemical management is deemed necessary, choosing the most effective but reduced risk chemical management option available. These considerations often need to be made with knowledge of the potential for environmental health and human health risks, water quality protection best practices, and conservation of non-target organisms in mind.
For more information about pesticide registrations in Massachusetts, as well as pesticide licensing and regulation, visit:
MA Department of Agricultural Resources Pesticide Program: https://www.mass.gov/orgs/pesticide-program
Registered Pesticides in Massachusetts: https://www.kellysolutions.com/MA/default.asp
For more information about pesticide active ingredients, modes of action, and risks to pollinators and other non-target organisms, visit: https://ag.umass.edu/landscape/fact-sheets/tree-shrub-insecticide-active-ingredients-risks-to-pollinators-other-non .
Need an insect pest of a tree or shrub identified? Submit a sample to the UMass Plant Diagnostics Laboratory: https://ag.umass.edu/services/plant-diagnostics-laboratory .