Thousands of papers and reports have been produced on the subject of the damage caused to agricultural crops, pasture lands and forests by locusts and grasshoppers throughout the world. Owing to the inaccessibility of much of this information, and the fact that it occurs in many languages, it was decided to summarize current knowledge concerning nearly five hundred species occurring in the developing world and nearby tropical and subtropical areas (see red area on map). The contents of the Manual have been selected to assist all those concerned with agricultural and extension services and the wider problems of rural development.
While this Manual is not intended to be either a taxonomic work or an identification handbook, the information given for each species includes its correct name and the more important ones by which it has been known in the past, together with a brief description and an indication of its size. As a further aid to identification, illustrations representing the different taxonomic groups and life-forms are given. Details of distribution are provided, including a map for most species. There are also sections covering life cycle, ecology, behaviour and, most important of all, the damage caused by each species. As the detail given in the original publications varies greatly, the economic importance of each species is presented on a nine-point scale covering the range from ‘major pest of many crops’ to ‘few records of minor damage’.
To assist the reader who requires more detail on any particular topic, the Manual contains not only a comprehensive Bibliography of nearly two thousand entries but also a separate list of publications relevant to each species. As the grasshoppers in this Manual have been arranged in systematic order so that related species appear near one another, rather than in alphabetical order, a comprehensive Index of Genera and Species (including synonyms) is provided, together with a Geographical Index.