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Forest Health

Frontal close-up photo of an Asian longhorned beetle
Asian longhorned beetle
Photo: NYS Museum

DEC's Forest Health program is responsible for monitoring the ecological health and function of the forests of New York State. The program gathers, analyzes, and reports on tree pest and disease information for public and private landowners and land managers. The highest priority is placed on early detection of and rapid response to high-impact invasive species that may threaten the health of our forests.

Wondering what's wrong with your tree? Learn how to contact the Forest Health Diagnostic Lab for identification assistance.

Forest Health Issues

Pests that Can Harm New York State Trees

Learn about the symptoms and signs, hosts, biology, and available control strategies of many of the harmful insects and diseases that threaten trees and forests in New York State. Damage can also be caused by environmental factors.


Forest tent caterpillar
Forest tent caterpillar


*Quarantine: when movement of certain articles is restricted in order to prevent the spread of a pest, disease or invasive plant.

DEC's Aerial Surveying Program

Defoliated deciduous trees seen during a summer flight

New York State is approximately 30 million acres in area, with 18.9 million acres of that area designated as forest. With such a large area for possible threats by insects, diseases, human activities and weather events, a comprehensive and expedient aerial survey plan was created to monitor for such damages.

Each summer DEC teams up with the New York State Police Aviation Unit to conduct a two-month aerial survey of the state's forests. The survey begins in the southern Hudson Valley near Newburgh and ends in the St. Lawrence Lowlands near Plattsburgh. The objective of the survey is to collect general information about forest health conditions for dissemination to state regional office foresters and private forest owners, annually. The data is used for forest management and monitoring at the state level, as well as the systemic tracking of possible causal agents, which threaten our forests on a national level.

More about Forest Health:

  • Insect, Plant and Plant Disease Identification at the Diagnostic Lab - Identification of insects, plants and tree and plant diseases
  • Oak Wilt - Oak wilt is an aggressive disease that affects many species of oak (Quercus spp.). It is a very serious tree disease in the eastern United States, killing thousands of oaks each year in forests, woodlots, and home landscapes.
  • Beech Leaf Disease - Beech leaf disease affects and kills both native and ornamental beech tree species.
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  • Contact for this Page
  • Lands and Forests
    625 Broadway
    Albany, NY 12233-4253
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