Diapause

Introduction

The term diapause mainly refers to the development of an animal. The development is seen at a particular stage until the organism passes the unfavourable conditions. The significance of this stage is that it describes the decrease of metabolic activities of an organism. The stage is important for overcoming the conditions like extreme temperature.

Overview of Diapause

Diapause mainly defines as a state of physiology that relates to dormancy. It is also called the developmental arrest and in this state, most of the life processes are shut down. The initiation of this stage has happened when the condition is unfavourable. This phase is mostly seen among insects and arthropods is an example of this factor. It is seen that diapause occurs in the cases of insects and within a selected group of vertebrates.

The observation is made that the stage of diapause can happen at any stage of an insect’s life cycle. The stages include the pupae stage to the active, adult stage. It is seen that the incident occurs when the stage lies in the stage egg or the pupil stage. In this stage, the development of the procedure slows down to a halt. In the stage of adulthood, the habits of feeding or reproductive behaviour mainly slow down or halted.

Organisms that exhibit Diapause

Different kinds of organism exhibit diapause and it is reported that the ever longest diapause belongs to the Prodoxus Y-inversus. It is a kind of moth that is widely found in South Western New Mexico and the United States. The specification of this moth is that it can remain in a state of dormant for 19 years.

In the stage embryological, diapause can mainly be seen in many arthropods. The arthropods are the tobacco hornworm, the flesh fly, and the Southwestern corn borer. A species of fish called mummichog goes through the process of diapause during the stage of their embryo phase. Silkworms are also seen in exhibiting diapause between the stages of late embryonic and late larval.

Stages of Diapause

Various stages of diapause help in understanding the matter very clearly and they are described below −

• Induction − This stage of induction happens before the onset of the condition of the environment that is not favourable. At this time, the stimuli of the environment named token stimuli mainly trigger the behaviour of the diapause. The stimuli do not affect negatively the factors but they signify the impending transformation of the conditions of the environment.

• Preparation − It is observed that the phase of induction is followed by the phase of preparation. This phase is mainly characterised by the storing molecules of the insects like lipids, proteins, as well as carbohydrates for sustaining during the phase of diapause.

• Initiation − This is called one of the most important phases of the stage and it is characterised by morphological development’s cessation. The phase includes the diapause stage’s moulting, colour change, as well as secretion of special enzymes.

• Maintenence − The stage of maintenance is mainly characterised by the low rate of metabolism as well as embryological development’s arrest. Hence, the sensitivity of different stimuli is increased and especially the ones that prevent termination face a decrease in diapause.

• Termination − The name of the stage suggests that it is a stage that terminates diapause. It is seen that some kind of insects remains on the stimuli of a specific environment for triggering the diapause’s termination.

• Post-diapause quiescence − The stage of termination follows the stage of quiescence and here insects mainly resume development. Some conditions of the environment are applied here and the conditions become favourable for the stage.

Difference between Hibernation and Diapause

Diapause as well as hibernation is called adaptations of animals in response to an environment that is harsh. There are various differences between the two factors and it is seen that diapause occurs in the cases of insects. This process happens during the stage of the development of an organism like the embryo stage. Hibernation is a bit similar to diapause but it is characterised by the low body temperature.

The differences between the two factors are described below with the presentation of a table −

Diapause	Hibernation
It is called a dormant stage and is found in an organism's development period.	It is called an organism’s decrease in metabolic activity.
It can happen at any time of the year.	This process happens in the month of winter.
It is seen among the insects.	It can be seen among higher animals and invertebrates like
Monarch butterflies is a kind of species that exhibit this process in the time of winter.	Some mammals like bats, prairie dogs and ground squirrels falls under this category.

Conclusion

This tutorial proves that diapause is a period of suspended development of an insect. Some other invertebrates as well as mammals go through the process. They go through the process during the unfavourable environmental conditions and the stage leads them towards development. This stage is also called the stage of suspended or arrested development.

FAQs

Qns 1. What is the importance of diapause for insects?

Ans. It is called an endogenously regulated dormant state that helps the insects to survive in unfavourable environmental conditions. This stage allows the insects to survive as well as reproduce and that is the importance of this stage.

Qns 2. Can humans have embryonic diapause?

Ans. It is called a period of embryonic suspension at the stage of blast cyst. This stage can occur among 130 species of mammals and humans also go through this process.