Diurnal rhythms of supercooling in locusts

When locusts are exposed to diurnal cycles of LD 6:18, which are known to elicit a clear circadian periodicity in these insects, the supercooling point is lower in the dark than in the light phase — significantly so in the case ofL. migratoria. The adaptive value of this is that it enables the animals to withstand colder conditions. It is argued that the rhythm is probably endogenous and coupled with the circadian locomotory rhythm.