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 ?
Wing dimorphism and diapause in Gerris: determination and adaptive significance.
rufimanus emerge from seeds and return to the overwintering sites to pass their diapause and then colonize crops.
After mating in special mating cages daughter queens were feed for about a week period and kept for diapause in refrigerator at 2.
Up-regulation of heat shock proteins is essential for cold survival during insect diapause.
hesperus adults will enter diapause as the seasons change and the days grow shorter.
These eggs were incubated at 20[degrees]C for a month before being chilled at 5[degrees]C for 3 months to terminate embryonic diapause (Tanaka 1992).
2002; Tzanakakis 1986) and is referred to as a summer reproductive diapause.
Diapause (die-a-paws) is the name given to the special kind of dormancy insects go through.
The shorter days of autumn trigger certain species of mosquitoes into diapause, a hibernation-like state of arrested development that allows them to survive through the winter, but this new research has determined that a hormonal response is behind the mosquito's ability to store up extra fat and halt reproductive activity in preparation for its months-long dormancy, explains David Denlinger, professor of entomology at Ohio State University, Columbus.
The different behaviors on the hatching response observed in the present study as a result of the interaction between the acclimatization and storage periods can be explained by differences in diapause intensity (banks, 1987).
They also mentioned that females remain in reproductive diapause from the end of June until April-May (end of dry season), and that breeding begins with the onset of the rainy season (May-June).