Cuban Laurel Thrips (Gynaikothrips ficorum) are a large thrip and a common pest on Indian laurel, weeping fig, India rubber plant, other figs, and various shrubs and herbs. They feed on leaves and cause spots and leaf galls.

Researchers have developed the Cuban Laurel Thrips growing degree day model, available on the Pest Prophet app, in order to help predict when different life stage events will occur, based on the weather.

Calculating Growing Degree Day Units

The Japanese Flower Thrips growing degree day model uses a lower threshold of 53.6F  and an upper threshold of 95F for calculating growing degree day units. The growing degree day units can be calculated from daily maximum and minimum temperatures using these thresholds, or by using the Pest Prophet app, which features this model and is easy to set up and use.

Setting the Biofix date

In order to begin growing degree day accumulation, first a “biofix” date must be set which is the first date, after which growing degree day units will begin to accumulate. In the Pest Prophet app, the biofix date can be adjusted for any observed life cycle stages.

For the Cuban Laurel Thrips model, in order to predict the emergence of next generation thrips, the biofix date should be set when first adults are observed. Approximately 442 GDD(F) after this biofix date, the next generation of adult thrips will emerge.

For best results the biofix should be re-adjusted for each generation, based on scouting observations. This will improve accuracy of later crop stage predictions.

Sources:

Paine, T. D. 1992. Cuban laurel thrips (Thysanoptera: Phalaeothripidae) biology in southern California: seasonal abundance, temperature dependent development, leaf suitability, and predation. Ann. Entomol. Soc. Am. 85: 164-172. “””,