The Mint Root Borer (Fumibotys fumalis) is an important pest on mint in some areas. Overwintered Mint Root Borer larvae typically emerge in spring and the first adults may be seen soon after. The Mint Root Borer Growing Degree Day Model, developed by researchers, 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, April 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.

After adults are observed and confirmed, the biofix can be adjusted in order to improve accuracy of the model for predicting later life stages.

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 emerge at 430 GDD (F) after the Jan. 1st biofix. These adults can be targeted for traps. Peak adult trap catch will occur at approximately 910 GDD(F) following the biofix date.

Source:

Berry et al. 2000. Mint Root Borer Growing Degree Day model.