Pull species phenophase onset dates from the USA-NPN Observational Data API to time pruning or pest treatments

Steps

1. Review USA-NPN's published Observational Data API documentation (linked from usanpn.org/data/code) to identify the individual- or site-phenometrics service you need.
2. Always populate the request_source parameter with your name or organization — USA-NPN uses an honor-system identification requirement instead of API keys.
3. Query by species_id (from USA-NPN's species list) and a date/year range to retrieve phenophase onset/end estimates (e.g. leaf-out, flowering, dormancy) relevant to pruning or pest-treatment windows.
4. For raster/gridded products (e.g. spring-onset anomaly maps) instead of point observations, use the separate Geoserver Request Builder at data.usanpn.org/geoserver-request-builder.
5. Reference the maintained rnpn R client's documented call patterns as an implementation guide if you're building a custom HTTP client in another language.