Encarsia formosa is an important insect used for biological control of Greenhouse Whitefly. Researchers have developed a growing degree day model for Encarsia formosa that can help predict adult emergence timing from eggs and nymphs, in order to improve pest management decisions.

Calculating Growing Degree Days

The Encarsia formosa model uses a lower threshold of 54.9F. 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.

For this model, the “biofix” date, or date from which to start accumulating growing degree days, should be set to when Encarsia formosa eggs are first observed or introduced to field.

First adult emergence occurs at approximately 340 GDD (F) after the biofix date.

Sources:

Osborne, L. S. 1982. Temperature-dependent development of greenhouse whitefly and its parasite Encarsia formosa. Environ. Entomol. 11: 483-485.