The Locust Borer (Magacyllene robiniae) is an important pest on black locust trees. Overwintered Locust Borer larvae typically emerge in spring and the first adults may be seen soon after. The Locust Borer Growing Degree Day Model, developed by researchers at Cornell Univserity, and available on the Pest Prophet app, is a tool growers can use to predict the onset and peak of adult trap catches using field-specific temperature data.

Initiating the Biofix

To properly use the model, the biofix must first be set. This is the date that will serve as the starting point for growing degree day accumulation. For this model, January 1st is the standard biofix to start accumulation (for the Northern Hemisphere). This can be used to predict when adults will emerge and pheromone traps can be used.

Growing Degree Day Accumulation and Treatment

After the biofix is set, growing degree day accumulation can begin, using a lower threshold of 50F. This can be done using daily high and low temperatures, or using hourly temperature data using the Pest Prophet app. Adults typically begin to emerge at 2272 GDD (F) after the Jan. 1st biofix, with emergence ending around 2805 GDD(F). These adults can be targeted for traps.

Source:

Kowalsick, Thomas, and Scott Clark. 2006. Using Growing Degree Days for Insect Pest Management. Cornell Cooperative Extension. 2006.