Vulnerability of alpine butterfly eggs to early winter warming.

ABSTRACT: Parnassius smintheus is an alpine butterfly that overwinters as a first-instar caterpillar within its egg and often beneath the snow. While extreme temperatures in early winter appear pivotal to year-to-year population change of P. smintheus in the Rocky Mountains of Canada, the sources of mortality for these eggs are unclear. Here we tested three hypotheses about the vulnerability of eggs to warming and extreme weather in early winter (i.e. upper quartile of daily maximum and minimum microclimate temperatures in November): (1) warming disrupts the acquisition of cold tolerance, making eggs susceptible to subsequent cold snaps; (2) warming drives premature development and hatch, such that precocious hatchlings either starve or freeze; and (3) warming depletes the energy store

SUBMITTER: Turnbull KF 

PROVIDER: S-EPMC12765160 | biostudies-literature | 2026

REPOSITORIES: biostudies-literature