USA NPN National Phenology Network

Taking the Pulse of Our Planet

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Gypsy moth catepillar, Image credit: Charles C. (Wikipedia)

Pheno Forecast maps estimate when plants and animals undergo key life cycle stages. For example, for spongy moth, the maps forecast when caterpillars will be present. 

Image credit:
David Cappaert,

Pheno Forecasts

The USA-NPN Pheno Forecasts indicate when insect pests and invasive species will reach life stages critical for monitoring and management in your region.

Bronze birch borer six day forecast

Bronze Birch Borer 6-Day Forecast.

Pheno Forecast maps predict the timing of key life cycle stages in key species to support agriculture and natural resource management. For insect pest species, Pheno Forecasts are based on published growing degree day (GDD) thresholds for life cycle stages. These key points typically represent life cycle stages when management actions are most effective. These maps are updated daily and available 6 days in the future.

Download the Pheno Forecast information sheet to learn more. 

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

Find out when to treat your trees for pests

Are you concerned about pests damaging your plants? Our insect pest maps help 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

Apple maggot

Asian longhorned beetle


Bronze birch borer


Eastern tent caterpillar

Emerald ash borer

Hemlock woolly adelgid

Lilac borer

Magnolia scale

Pine needle scale

Red brome

Spongy moth

Winter moth

Winter wheat

More Information 

Insect pest forecasts are based on accumulated warmth, using the USA-NPN Accumulated Growing Degree Day (AGDD) map products and published GDD thresholds. References for the published thresholds used to generate the forecasts appear on the individual species pages.

The invasive buffelgrass forecast is based on rainfall accumulation thresholds that are known to trigger green-up to optimize treatment and control. 

The winter wheat development forecast is based on accumulated warmth, with corrections for daylegth and chilling.

These maps are intended to provide a broad-scale prediction regarding when management action may be necessary and are intended to supplement local knowledge. Forecast accuracy may vary locally based on microclimatic variation. In addition, thresholds may perform with variable accuracy across species ranges. For more information about these pests and others specific to your state, contact your local Cooperative Extension program.

We invite your feedback on the performance of these forecasts at your location. You can help us improve the accuracy of these forecasts by letting us know when invasive and pest species undergo life cycle stages at your location. You can report observations of all Pheno forecast species in Nature's Notebook via the Pest Patrol campaign. 

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 the 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). See our Data Use Policy for suggested citation and attribution of the underlying data products.