Predicting Insect Stages Using Degree Days

Simply put a degree day is the accumulation of heat after a set temperature. Insect development is usually calculated on a base of 50 degrees. Degree days are a more accurate way of predicting insect development than are dates because temperatures vary each year. For many of our common pests scientists have calculated what stage of development an insect is in for specific degree days.

Knowing what stage a pest is in is important because most insects are much more susceptible to control measures in one life stage than in others. Scale for example is very difficult to control as an adult, yet fairly easy to control in its juvenile stage (called a crawler). Some universities and other agencies have monitors in various locations that calculate and report degree days. The University of New Hampshire does this for where I live.

Download my Insect Development Timing Chart.

One response to “Predicting Insect Stages Using Degree Days”

  1. […] keeping and dates of hatch can help in timing insect stages but the most reliable method is using degree-days, the next best method is using bloom time (phenology). (This link is from Ohio but phenology and […]

Leave a Reply

Your email address will not be published. Required fields are marked *