The Spotted Lanternfly is an invasive insect in the United States, that has cause a lot of damage since it was first discovered in Pennsylvania in 2014. Spotted Lanternfly has a wide host range, feeding on over 100 different types of plants, including grapes, fruit trees, hops, and maple trees. The insect’s feeding can damage plants and make them more susceptible to diseases. Spotted Lanternfly overwinters as egg masses and there are two phases, diapause and development stage. After the development stage, Nymphs emerge and may be targeted for treatment.

The Spotted Lanternfly Degree Day Model, developed by researchers, and available on the Pest Prophet app, is a tool growers can use to time predict development phase and nymph emergence.

Initiating the Biofix

To properly use the model, the biofix must first be set. This is the date that will serve as the starting point for growing degree day accumulation. For this model, the first date that egg masses are observed should be used for the biofix date. Alternately, September 15 can be used as a ‘default’ date for the biofix.

Growing Degree Day Accumulation and Treatment

After the biofix is set, growing degree day accumulation can begin, using a lower threshold of 7.36 C. Calculating growing degree days can be done using daily high and low temperatures, or using hourly temperature data using the Pest Prophet app. The development phase begins at approximately 171 GDD(C) and ends after an additional 446 GDD (C). After this, nymphs emerge and they can be targeted for treatment.

Source:

Keena, M.A. and Nielsen, A.L. 2021. Comparison of the Hatch of Newly Laid Lycorma delicatula (Hemiptera: Fulgoridae) Eggs From the United States After Exposure to Different Temperatures and Durations of Low Temperature. Environ. Entomol. 50: 410-417.

Kreitman, D., Keena, M.A., Nielsen, A.L., and Hamilton, G. 2021. Effects of Temperature on Development and Survival of Nymphal Lycorma delicatula (Hemiptera: Fulgoridae). Environ. Entomol. 50: 183-191.