Once diapause has begun, metabolic activity is suppressed even if conditions favorable for development prevail. Second, the environmental signals that are translated into a diapause syndrome are called token stimuli because they do not themselves impact on insect life. Token stimuli simply herald the coming changes. Third, the definition is biologically large because it includes dormancy and seasonal migration and seasonal polyphenism. To keep our terms straight, let us agree that dormancy is a period in a life cycle during which growth, maturation and reproduction are held in check.
Dormancy can occur in any season.
Polyphenism refers to seasonal changes in color or structure of an organism. Fourth, the events in a dispause syndrome are not aimed directly at organismal survival during any particular set of environmental conditions. Diapause has more to do with synchronization of entire life cycles to seasonal changes in environments. It affects survival during unfavorable conditions, but it also bears a large weight upon other features of life history, including growth, development and reproduction. Hence, diapause is a unifying biological concept.