Parnassius smintheus overwintering project
Parnassius smintheus is a high altitude butterfly which lives in the Rockies (US and Canada). The caterpillars feed on the leaves of the succulent Sedum lanceolata, and the adults feed on its nectar. Over the last 20 years, there has been dramatic variation in population growth from year to year, yet it seems that the drops in population correspond to years with excessively warm Novembers. The general hypothesis is that the warm Novembers affect the larvae's ability to survive the winter. The aim of the project is to determine the exact way in which warm Novembers affect the mechanisms of overwintering.
Understanding the mechanisms which these butterflies use to survive the winter is essential for their conservation (this is the primary focus of my collaborators in the Matter lab). Yet this project also has implications for insect thermobiology more generally. As the climate is rapidly changing, it is important to understand the ways in which overwintering conditions affect survival and population processes in different insects, in order to be able to predict and manage insect populations in the (near) future (this is the primary focus of my collaborators in the Sinclair lab)
I have collected P. smintheus eggs from the field site in Kananaskis AB. They will incubate in realistic ecological conditions (variable night and day temperatures, variable humidity) until November. Then, the eggs will be divided into two groups: the control will incubate at standard (cool) November temperatures while the experimental group will incubate in a warm treatment. After that, all the eggs will continue incubating at realistic ecological conditions, simulating winter and spring temperatures, until they hatch. I will conduct a number of parallel experiments on the two different groups, including:
- Measurement of energy reserves and cryoprotectants
- Measurement of Supercooling Points
- Survivorship after hatching
I am indebted to the Sinclair lab (Western University) and the Matter lab (University of Cincinnati) for introducing me to these ideas, helping me out and for putting up with and engaging with an interminable number of philosophical questions.