Winter Moth Pheno Forecast, Contiguous United States, Current Year and Prior Year

Pheno Forecast maps predict key life cycle stages in a range of species to improve conservation and management outcomes. For insect pest species, Pheno Forecasts are based on published growing degree day (GDD) thresholds for key points in species life cycles. These key points typically represent life cycle stages when management actions are most effective. Winter moth caterpillars can defoliate certain species of deciduous trees. Some control measures are most effective when caterpillars emerge.

We forecast caterpillar emergence in winter moth (Operophtera brumata) at 20-350F growing degree days (base 50F, start date: January 1, simple average GDD method). These maps are updated daily and available 6 days in the future.

Forecasts are available for the current and prior year in the USA-NPN Visualization Tool (https://www.usanpn.org/data/visualizations).

For all inquiries regarding this dataset, please contact the USA-NPN. This data is subject to the USA-NPN's Data Use Policy.