> For example,
an under-bark temperature of –37°C will
kill 50 per cent of a mountain pine beetle
population, even in mid-winter; however, a
low temperature of –20°C in the fall, be-
fore the beetles are prepared for winter,
or in the spring, when beetles are start-
ing to become more active, will also kill
beetles if it is preceded by temperatures
above 0°C. The relatively warmer temper-
ature causes the larvae to start to lose its
natural antifreeze.
https://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/fo...
> For example, an under-bark temperature of –37°C will kill 50 per cent of a mountain pine beetle population, even in mid-winter; however, a low temperature of –20°C in the fall, be- fore the beetles are prepared for winter, or in the spring, when beetles are start- ing to become more active, will also kill beetles if it is preceded by temperatures above 0°C. The relatively warmer temper- ature causes the larvae to start to lose its natural antifreeze.