Host selection; Size in aphids; Polymorphism; Cyclical parthenogenesis; Life-history patterns; Dispersal; Population dinamics; Community structure and species diversity; Epilogue.

Biology of the cereal aphid system; The model; Results; General discussion.

Aphids are tempting subjects for investigation because they are often abundant, easily found, and unlikely to run away, and because of intriguing facts about their biology such as polyphenism, parthenogenesis, gall formation, and the production of a soldier morph. However, until now identification has presented a severe challenge to the beginner, because there are so many rather similar species, many of which have several different forms. The authors make this much needed Naturalists' Handbook accessible by confining themselves to aphids leaving on broad-leaved trees. This has reduced the problems of identification to manageable proportions and should encourage more field studies of this important and ubiquitous group of insects.

Tony Dixon analyses long-term population studies and experiments showing that tree dwelling aphids are regulated not by natural enemies but by competition for limited resources. This book is designed to introduce students and research workers to insect herbivore-host dynamics using the interaction between aphids and trees as a model.