Diapause


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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 ?
In autumn maturing cohorts, most individuals mature between March and May, enter winter diapause, reproduce only after over-wintering and die by December.
For diapause induction, 6th instars were placed in an 18 [+ or -] 1[degrees]C controlled-temperature room with an 8:16 h L:D photoperiod, and the diapause status of the pupae was ascertained as previously described (Liu et al.
Evolutionary relationship between diapause and cold hardiness in the house spider Achaearanea tepidariorum (Araneae: Theridiidae).
quinquefasciatus (the presumed vector of WNV in the region) does not enter a true diapause, as does its northern counterpart, (2.
Researchers had to learn and are still learning about such traits as how far boll weevils will travel, especially in the face of strong winds; what other plants attract them; and the insects' diapause, or winter dormancy.
Changes in free amino acids of hemolymph of Antheraca perunji during induction and termination of diapause.
Reproductive diapause in Hippodamia convergens (Coleoptera: Coccinellidae) and its life history consequences.
These events occurred approximately 7 months after the termination of reproductive diapause (22) and 2 months after the vernal peak in the Cx.
Most grasshopper eggs spend the winter in the soil after a temperature-driven dormancy called diapause, says Fisher.
Neonicotinoid insecticides alter diapause behavior and survival of overwintering white grubs (Coleoptera: Scarabaeidae).
The bird-biting mosquitoes live and breed in open areas above-ground and diapause during the winter; human-biting mosquitoes live exclusively in enclosed areas, like the underground rail lines, that are kept warm year-round.
So the weevils are without a host during a cool spell and go into diapause.