Serpentine Fruit Flies are an important economic pest on a variety of fruits and berries in Mexico and other tropical areas. Researchers have developed a growing degree day model for Serpentine Fruit Fly that can help predict when eggs will hatch, and the next generation of adults will emerge. However, researches have found that the host can affect growth rate, so they have developed specific models for Peaches and Chicozapote/ Sapodilla.

Calculating Growing Degree Days

The Serpentine Fruit Fly model uses a lower threshold of 8.8 C for Peach and 10.2C for Chicozapote/ Sapodilla. 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 larvae will begin to emerge at 78 GDD (C) for Peach and 211 GDD (C) for Chicozapote/ Sapodilla. Pupation occurs at 393 GDD (C) for Peach and 279 GDD (C) for Chicozapote/ Sapodilla. Adults will emerge at 685 GDD (C) for Peach and 535 GDD (C) for Chicozapote/ Sapodilla.

Sources:

Shaw, J. G., and D. F. Starr. 1946. Development of the immature stages of Anastrepha serpentina in relation to temperature. Journal of Agricultural Research 72: 265-276.