Diapause


Also found in: Dictionary, Medical, Wikipedia.
Related to Diapause: aestivation

diapause

[′dī·ə‚pȯz]
(physiology)
A period of spontaneously suspended growth or development in certain insects, mites, crustaceans, and snails.

Diapause

 

a period of rest in the development of animals, characterized by a sharp decline in metabolism and a halt in formative processes. Sometimes the concept of diapause is extended to other organisms.

During diapause the organism is more resistant to unfavorable external conditions. For example, insects become resistant to insecticides. In the temperate and high latitudes the onset of diapause in many animals is determined by the length of daylight. The termination of diapause is connected with changes in the organism, which may be caused by the prolonged action of low winter temperatures. Thus, diapause ensures the animal’s ability to withstand below-freezing temperatures and hibernation. In arid subtropical and tropical climates, summer diapause, or estivation, occurs (for example, in the pink bollworm and the tomato fruitworm).

In each biological species diapause is timed to a certain phase in the life cycle. Embryonic diapause is the period of rest in the egg stage between fertilization and mitosis or toward the end of mitosis. This type of diapause occurs in rotifers, lower crustaceans, grasshoppers, Chinese silkworms, and in a number of mammals belonging to seven orders (for example, rodents and predators, including sable and mink). Larval diapause occurs, for example, in the black-veined white butterfly, which hibernates in trees during the caterpillar stage. Pupal diapause is observed among large white cabbage butterflies and cabbage moths, which hibernate in trees and in the soil during the pupal stage. Imaginal diapause occurs in such insects as mosquitoes and leaf beetles (Colorado beetles). In imaginal diapause the animal may retain its mobility, but the process of sexual maturation ceases.

V. A. SVESHNIKOV

References in periodicals archive ?
undergo diapause in winter season and convert into adult only
However, the largest migration occurs during the preadult copepodite stage (CV), which moves to deep waters (150-1000 m) to undergo a period of diapause (for review, see Hirche, 1996).
Eggs from this strain do not enter embryonic diapause at 30 [degrees]C and hatch in 14-15 days.
The trehalase gene was expressed in non-diapause eggs of the multivoltine silkworm Bombyx mori for 9 days, whereas that in the diapause eggs was not upregulated.
avenae depend upon specific temperature conditions breaking one type of diapause, obligatory and in summer for the two populations originating from Oued Smar in a sub-humid coastal plain and from Tiaret in an inland semi-arid plain [14].
2001: Temporal changes in reproductive hormones and conceptus-endometrial interactions during embryonic diapause and reactivation of the blastocyst in European roe deer (Capreolus capreolus).
This week British and American scientists reveal that mimicking a natural process called diapause can halt stem cells, effectively putting them to sleep for up to two weeks.
Embryo development was similar to that of other cold-water crab species, with the exceptions that 1) golden king crab did not have a diapause and 2) that the average percentage of the area occupied by the yolk at hatching, at about 40%, was much higher than that of other species.
Pupae overwinter in diapause (a resting state) inside silken cocoons in protected locations, such as under the bark of the vine.