Conserved and narrow temperature limits in alpine insects: Thermal tolerance and supercooling points of the ice-crawlers, Grylloblatta (Insecta: Grylloblattodea: Grylloblattidae)

摘要: For many terrestrial species, habitat associations and range size are dependent on physiological limits, which in turn may influence large-scale patterns of species diversity. The temperature experienced by individuals is considered to shape the breadth thermal niche, with occupying temporally and/or geographically stable climates tolerating a narrow range. High-elevation environments experience large fluctuations, frequent periods below 0 °C, but Grylloblatta (Grylloblattodea: Grylloblattidae) occupy climatically microhabitats within this region. Here we test critical limits supercooling points for five populations from across geographic area, examine whether group associated niche assess their capacity tolerate cold conditions. Thermal highly conserved Grylloblatta, despite substantial genetic divergence among spanning 1500 m elevation being separated over 500 km. Further, show exceptionally compared other insect taxa little improve tolerance via plasticity. In contrast, upper were significantly depressed acclimation. maintain coordinated movement until they freeze, die upon freezing. Convergence minima, point lower lethal adaptation but, importantly, constant environment. These data provide an explanation high endemism patchy distribution relies subterranean retreats accommodate limits. currently buffered fluctuations snow cover, declining snowpack thus places at risk exposure temperatures beyond its capacity.