Fenders Blue Butterfly (Kincades Lupine) is endangered species in Pacific Northwest. Researchers at Oregon State University have developed a growing degree day model for Fenders Blue Butterfly to help predict when different life cycle stages will occur, which is helpful for observing the Fenders Blue Butterfly.

Calculating Growing Degree Day Units

The Fenders Blue Butterfly growing degree day model uses a lower threshold of 41F 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 Fenders Blue Butterfly model, the biofix date should be set to Feb. 15th for the Northern Hemisphere, in order to predict the emergence of adults from overwintered larvae, and the following generations. Approximately 678 GDD(F) after the Feb. 15th biofix date the first adults from overwintered larvae will be observed.

Sources:

Len Coop, OSU IPPC Feb. 2012, data coordinated by Greg Fitzpatrick, Fitzpatrick Ecological Consulting LLC