Shield bug and butterfly
The brimstone butterfly (left) and the green shield bug (right) pass the winter when they are fully grown and hiding in the vegetation. The pine hawk moth (right) rests as a pupa dug in the ground.
Don't they die?
Brimstone butterfly and pine hawk moth can withstand low temperatures without dying. Insects' body fluids normally freeze at one degree below Celsius, but it changes in the winter: glycerol and such substances are mixed with the body fluids. The brimstone and pine hawk moth's body temperatures do not freeze until it is ten to fifteen degrees Celsius below zero.
