UW Extension Ag Weather offers Wisconsin weather station data and interactive insect degree day thermal model tools to assist you in making informed pest management decisions based on conditions at your location.
- About insect degree days
- How to calculate degree days
- Degree day calculator
This interactive tool allows you to input your Wisconsin or Minnesota location to the nearest latitude and longitude coordinates, method of degree day calculation, and appropriate biofix date. The degree day calculator gives degree days in Fahrenheit units. Be sure to use the Fahrenheit scale when using this degree day calculator. It takes nine Fahrenheit degree days (FDD) to make five Celsius degree days (CDD).
CDD = 5/9(FDD), and FDD = 9/5(CDD).
Field and forage crop insect degree day models
Photo: UW Madison
Alfalfa Weevil Thermal Model
Alfalfa weevil degree day model, accumulated degree day map display, information, and instructions allow you to predict alfalfa weevil development in the field to guide IPM scouting and economic threshold treatment decisions in alfalfa.
Photo: Sarah Schramm
Seedcorn Maggot Thermal Model
Seedcorn maggot is an occasional soil insect pest of soybean, corn and vegetable crops. Adult flies lay eggs in freshly plowed fields with decaying green plant material associated with spring cover crop incorporation or weed tillage. The seedcorn maggot degree day model, accumulated degree day map display, information, and instructions allow you to plant crops during the “fly-free” period between seedcorn maggot generations.
Photo: UW Madison
European Corn Borer Thermal Model
Critical degree day accumulation values for first and second generation European corn borer are listed along with an accumulated degree day map display to help target scouting and economic threshold treatment windows for this corn stalk boring and ear pest.
Photo: James Kalisch
Stalk Borer Thermal Model
Stalk borer is increasingly a significant pest in fields managed with reduced tillage. Eggs are laid during late summer and fall in grassy areas within and adjacent to corn fields, then hatch in spring. This accumulated degree day map display, information, and instructions forecast movement of larvae from grassy areas into corn fields, allowing you to scout and plan control measures if needed.
