Degree-day

Definition

A unit of measurement used in entomology to quantify the amount of heat required for insect development.

Etymology

From the combination of 'degree' and 'day', signifying the unit of temperature accumulation over a day.

Example

The development of a certain insect species requires 100 degree-days to complete its life cycle.

Related Terms

• Thermal summation
• Development rate
• Threshold temperature

Usage Notes

Degree-days are calculated by subtracting a lower developmental threshold temperature from the average daily temperature. If the difference is less than zero, the degree-day value for that day is set to zero.