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The population dynamics of pest insects is a subject of interest to farmers, agricultural economists, ecologists, and those concerned with animal welfare. ==Factors affecting populations== * Density-independent: Affect a population equally regardless of its density. Examples: * * A winter freeze may kill a constant fraction of potato leafhoppers in a peanut field regardless of the total number of leafhoppers. * * Japanese beetle larvae survive well with lots of summer rain. * * Temperature, humidity, fires, storms, dissolved oxygen for aquatic species. * Density-dependent: Affect a population more or less as the population is bigger. Examples:〔 * * A bigger population may be more vulnerable to diseases and parasites. * * A bigger population may have more intraspecific competition, while a smaller population may have more interspecific competition. * * Emigration from the population may increase as it becomes more crowded. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pest insect population dynamics」の詳細全文を読む スポンサード リンク
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