Oriental 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 Oriental Fruit Fly that can help predict when eggs will hatch, and the next generation of adults will emerge.

Calculating Growing Degree Days

The Oriental Fruit Fly model uses a lower threshold of 12.8 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 20 GDD (C).

Sources:

Messenger, P. S. and N. E. Flitters. 1958. Effect of constant temperature environments on the egg stage of three species of Hawaiian fruit flies. Ann. Ent. Soc. Amer. 51: 109-119.