The Sugarbeet Root Maggot (Tetanops myopaeformis) is a small fly that is a pest sugarbeets. Larvae feed on the roots, causing plant death in cases of severe infestation.

Sugarbeet Root Maggot Life Cycle Stages

Sugarbeet Root Maggots overwinter as larvae, before emerging in late Spring.

Researchers have created the Seedcorn Root Maggot Growing Degree Day Model to better predict when the adults will emerge from the soil, and when fly catch will occur.

Calculating Growing Degree Day Units

The Seedcorn Root Maggot Growing Degree Day model uses a lower threshold of 47.5 F. It can be calculated with daily high and low temperatures, using the sine model to estimate growing degree day units, or the Pest Prophet app can be used to calculate GDD accumulation from hourly temperature data for a specific field.

The “biofix” date, or starting point for accumulation, should be set to March 1st, for the Northern Hemisphere. Peak capture of adult flies will occur at approximately 361 GDD (F) after the biofix.

Source:

E. J. Bechinski, C. D. McNeal, J. J. Gallian, Development of Action Thresholds for the Sugarbeet Root Maggot (Diptera: Otitidae), Journal of Economic Entomology, Volume 82, Issue 2, 1 April 1989, Pages 608–615, https://doi.org/10.1093/jee/82.2.608