Sunn Pest (Eurygaster integriceps) is an important pest on barley and wheat in many areas. Overwintered adults will typically emerge in spring before arriving in a wheat or barley field before reproducing. The Sunn Pest Growing Degree Day Model, developed by researchers, and available on the Pest Prophet app, is a tool growers can use to predict adult arrival in spring, as well as larvae and adult emergence of the following generation.

Initiating the Biofix

To properly use the model, the biofix must first be set. This is the date from which growing degree days begin to accumulate. For this model, January 1st is the recommended biofix date, in order to predict adult emergence in spring, as well as larvae and adults of following generations.

Growing Degree Day Accumulation and Treatment

After the biofix is set, growing degree day accumulation can begin, using a lower threshold of 54F and an upper threshold of 97F. This can be done using daily high and low temperatures, or using hourly temperature data using the Pest Prophet app. First overwintered adults will arrive at approximately 180 GDD (F). Egg hatching / larvae emergence, and adult emergence of following generations can all be tracked using the model.

Source:

Kivan, M. 2008. Development rate and lower temperature threshold in the eggs of Eurygaster integriceps (Heteroptera: Scutelleridae). Insect Science 15:163-166.