一、农业昆虫的生活史对策 芸芸万类的农业昆虫有着各自的生物学特征。农业昆虫的生物学特征是由遗传性决定的。在长期进化过程中,昆虫可以通过改变它们的个体大小、年龄组配、存活率、扩散能力以及基因频率等来调整自己,使其与环境条件相适应。昆虫在不同生态环境中,向着不同方向演化,这就是通常所说的昆虫生活史对策。 在自然界中,按照昆虫种群特征可划分成两个适应类型,或称为两个不同的进化方向,生态学上称为r选择类和K选择类昆虫。一般认为,r类昆虫的生活环境常常是多变的、不稳定的。在这种生态条件下,自然选择对内禀增长率r_m值大的种群有利,所以只要环境条件(食料、温度、湿度等)适合,种群增殖极快。这类害虫常常体型偏小,寿命 First, the history of agricultural insects countermeasures Mian Wan agricultural insects have their own biological characteristics. The biological characteristics of agricultural insects are genetically determined. In the long-term evolutionary process, insects can adapt themselves to environmental conditions by changing their individual size, age distribution, survival rate, proliferative capacity, and gene frequency. Insects in different ecological environment, evolved in different directions, which is commonly referred to as insect life history strategy. In nature, according to insect population characteristics can be divided into two adaptive types, or two different evolutionary direction, ecologically known as the r-selected and K-selected insects. It is generally believed that the living environment of r-type insects is often volatile and unstable. Under such ecological conditions, natural selection is beneficial to populations with large rm values ​​of intrinsic rate of growth, so populations proliferate very fast as long as environmental conditions (foodstuffs, temperature, humidity, etc.) are suitable. Such pests are often small size, life expectancy