Katherine Dearborn, Myself and Richard Westwood use the temperature recorded at a nearby weather station to estimate the number of degree days accumulated by endangered Oarisma poweshiek, Hesperia dacotae and Erynnis martialis in Manitoba, Canada (following the methods in Dearborn and Westwood 2014). We then predict when the first adults will emerge. These predictions help several individuals and organisations (government, non-profit, and university) in Canada and the United States synchronise annual population and distribution surveys with the dates that these species are flying. These surveys are used by partners to monitor changes amongst and within populations. Below is a link to a representative prediction:

Dearborn, K., Henault, J. and Westwood, R. 2014-present (three times annually). Predicted emergence of adult Lepidoptera-at-risk in Manitoba, Canada. Prepared for endangered butterfly research groups. Spreadsheet (.xlsx), 1 sheet.
Hesperia dacotae (Dakota skipper), resting on Black-eyed susan (Rudbeckia hirta). Tall grass prairie, Manitoba, Henault, endangered, species-at-risk
Dakota skipper (Hesperia dacotae, female) resting on a Black-eyed susan (Rudbeckia hirta)

Anecdotally, these predictions are within a couple days of when adults emerge in natural habitats. However, I would like to know how accurate are they? Myself, KD and RW are currently analysing these predictions over approximately 15 years, to determine their accuracy and trial alternatives that may improve our predictions. We are currently preparing this manuscript, so please visit regularly for the published link!

Partner organisations where we send predictions (If I have missed you, sorry in advance! Please let me know and I will update this list.)

Canada

Assiniboine Park Zoo

Canadian Wildlife Service – Environment and Climate Change Canada, Gov.

Living Prairie Museum – City of Winnipeg

Nature Conservancy of Canada

Prairie Shore Botanicals

University of Winnipeg

Wildlife, Fisheries and Resource Enforcement Branch – Government of Manitoba

United States

Central Michigan University

Michigan Natural Features Inventory

Michigan State University

Minnesota, Wisconsin and Michigan respective Departments of Natural Resources

Minnesota Zoo

Minot State University

United States Fish and Wildlife Service

Springfield Township

Several additional invaluable contractors

References
Dearborn, K. and Westwood, R. 2014. Predicting adult emergence of Dakota skipper and Poweshiek skipperling (Lepidoptera: Hesperiidae) in Canada. Journal of Insect Conservation, 18: 875-884. https://doi.org/10.1007/s10841-014-9695-8.