From Wikipedia, the free encyclopedia
Look up diapause in Wiktionary, the free dictionary.
Part of a series on
- Winter rest
- Critical thermal maximum
- Sleep (non-human)
- Developmental biology
 It is considered to be a physiological state of dormancy with very specific initiating and inhibiting conditions. Diapause is a mechanism used as a means to survive predictable, unfavorable environmental conditions, such as temperature extremes, drought, or reduced food availability. Diapause is most often observed in arthropods, especially insects, and in the embryos of many of the oviparousspecies of fish in the order Cyprinodontiformes. (Diapause does not occur in embryos of the viviparous andovoviviparous species of Cyprinodontiformes.)
Diapause is not only induced in an organism by specific stimuli or conditions, but once it is initiated, only certain other stimuli are capable of bringing the organism out of diapause. The latter feature is essential in distinguishing diapause as a different phenomenon from other forms of dormancy, such as stratification and hibernation.
Activity levels of diapausing stages can vary considerably among species. Diapause may occur in a completely immobile stage, such as the pupae and eggs, or it may occur in very active stages that undergo extensive migrations, such as the adult Monarch butterfly, Danaus plexippus. In cases where the insect remains active, feeding is reduced and reproductive development is slowed or halted.