Mediterranean Fruit Flies are an important economic pest on a variety of fruits and berries in tropical areas. Researchers have developed a growing degree day model for Mediterranean Fruit Fly that can help predict when eggs will hatch, and the next generation of adults will emerge.

Calculating Growing Degree Days

The Mediterranean Fruit Fly model uses a lower threshold of 9.7 C. 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 date from which to start accumulating growing degree days, should be set when adults or eggs are first observed. After this the first new generation of adults will begin to emerge at 326 GDD (C).

Sources:

Tassan, R. L., K. S. Hagen, A. Cheng, T. K. Palmer, G. Feliciano and T. L. Bough. 1982. Mediterranean fruit fly life cycle estimations for the California eradication program. CEC/IOBC Symposium Athens November 1982. pp. 564-570.