Dormancy

Abstract

On most land surface, periods which are favourable for growth and morphogenesis alternate with unfavourable periods. In insects (as in other animals and plants) this has led to the evolution of appropriate annual life-cycles. The period of favourable environmental conditions (i.e. sufficient food and suitable physical factors) must be utilized for active life, i.e. for growth and development (of preimaginal stages and adults) made possible by adequate feeding. It is advantageous for a species to bridge the unfavourable period in a more or less inactive state in a stage which in some way has an increased survival potential. The presence of reserves and a reduced metabolic rate makes survival possible over a long period without feeding; different adaptations increase resistance to unfavourable physical conditions.