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Recent studies have shown that genetic polymorphisms play an important role in structuring the seasonal life cycles of insects, complementing an earlier emphasis on the effects of environmental factors. This book presents current ideas and recent research on insect life--cycle polymorphism in a series of carefully prepared chapters by international experts, covering the full breadth of the subject in order to give an up-to-date view of how life cycles are controlled and how they evolve. By consolidating our view of insect life--cycle polymorphism in this way, the book provides a staging point for further enquiries. The volume will be of interest to a wide variety of entomologists and other biologists interested in the control and evolution of life cycles and in understanding the extraordinarily complex ecological strategies of insects and other organisms.

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Preface. Insect life--cycle polymorphism: Introduction; S. Masaki, W. Wipking. Diversity and integration of life--cycle controls in insects; H.V. Danks. Seasonal plasticity and life--cycle adaptations in butterflies; S. Nylin. Evolutionarily stable aseasonal timing of univoltine and bivoltine insects; Y. Iwasa, H. Ezoe, H. Yamauchi. Variation of carabid life cycles along climatic gradients: an adaptive perspective for life--history evolution under adverse conditions; T. Sota. Variation in diapause characteristics and its consequences on population phenomena in the two-spotted spider mite, Tetranychus urticae Koch; A. Takafuji. Climatic legacies and sex chromosomes: latitudinal patterns of voltinism, diapause, size, and host-plant selection in two species of swallowtail butterflies at their hybrid zone; J.M. Scriber. Diapause as a pivotal factor for latitudinal and seasonal adaptation in Locusta migratoria in Japan; S. Tanaka. Summer diapause in the polymorphic life cycle of the noctuid moth Mamestra brassicae; C. Grüner, S. Masaki. Life--history variation in Dolichopoda cave crickets; C. Di Russo, G. Carchini, V. Sbordoni. Life--history patterns in 15 populations of Protohermes (Megaloptera: Corydalidae): effects of prey size and temperature; F. Hayashi. Production of alatae in response to low temperature in aphids: a trait of seasonal adaptation; S.S. Liu. Wing dimorphism and migration in the brown planthopper, Nilaparvata lugens St†l; G.R. Wu, X.P. Yu, L.Y. Tao, Z.J. Ren. Seasonal time partitioning and polymorphism in the developmental cycles of sympatric Staphylinoidea (Coleoptera) living in an unstable environment; W. Topp. Control of alternate-year flight activities inhigh-alpine Ringlet butterflies (Erebia, Satyridae) and Burnet moths (Zygaena, Zygaenidae) from temperate environments; W. Wipking, C. Mengelkoch. Insect life--cycle polymorphism: Current ideas and future prospects; H.V. Danks. Index.

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