USA NPN National Phenology Network

Taking the Pulse of Our Planet

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Pheno Forecasts

The USA-NPN Pheno Forecasts can help you determine when it is time to treat insect pests. 

Pheno forecast maps show when management actions should be taken for key pest species. These maps are updated daily and are available 6 days in the future.  Pheno forecasts are based on published growing degree day (GDD) thresholds for points in pest life cycles when management actions are most effective.

Help us improve these maps! Our pheno forecast map products are still in development, and we seek input on their performance in your area.

Find out when to treat your trees for pests

Are you a land manager, forester, planner, arborist, grower, or extension agent?  These maps will help you determine when your site will reach critical heat accumulation for the detection, management, and treatment of insect pests.  Maps are available via the USA-NPN visualization tool and on the individual species landing pages below. 

Available maps

Emerald Ash Borer
Winter Moth
Hemlock Woolly Adelgid
Lilac Borer
Apple Maggot

More Information

These forecasts are based on USA-NPN Accumulated Growing Degree Day (AGDD) map products.  For winter moth and hemlock wooly adelgid we encourage the collection of ground observations to be entered into the USA-NPN citizen science observation platform Nature's Notebook so forecasts can be verified and improved. 

Re-use of Maps and Data

Content, maps and data accessible via are openly and universally available to all users. USA-NPN is not responsible for content or the use of the data. Content may be re-used and modified with appropriate attribution (e.g., "source: USA National Phenology Network,"). See our complete Content Policy and Data Use Policy.