The Meadow Spittlebug (Philaenus spumarius) is a common pest on a wide variety of plants. There are more than 400 known hosts. They can be very challenging to control, and different insecticide products may target different life cycle stages (eggs, nymphs, adults) and not affect the pest at the other life cycle stages. For this reason, predicting when different life cycle stages will occur, based on current observations and weather data, can be very helpful. Researchers have developed a growing degree day model for Meadow Spittlebug to help predict when different life cycle stages will occur.

Calculating Growing Degree Day Units

The Meadow Spittlebug growing degree day model uses a lower threshold of 37F and an upper threshold of 80F or 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 Meadow Spittlebug model, the biofix date should be set when the first generation of adults, or eggs are observed. They will then progress through 5 different nymphal instar stages. At approximately 1390 GDD (F) the next generation of adults will be observed.

Sources:

Zajac, M. A., F. R. Hall, and M. Curtis Wilson. 1989. Heat unit model for the development of meadow spittlebug (Homoptera: Ceropidae) on strawberry. Environ. Entomol. 18: 347-350.,\

Chmiel, S. M., and M. Curtis Wilson. 1979. Estimation of the lower and upper developmental threshold temperatures and duration of the nymphal stages of the meadow spittlebug, Philaenus spumarius. Environ. Entomol. 8: 682-685.