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在害虫防治工作中,首先要掌握昆虫种群密度动态。然而大范围地对种群密度进行全面调查,既花工又可能延误防治时机,所以一般采用抽样方法,以样本值来估计总体值。但因不了解昆虫种群空间结构的概率分布情况,仅用五点取样、对角线取样等方法,样本值与实际总体值之间往往有很大差误的,甚至完全不能反映总体的真实情况。如果以此种数据为依据,开展研究(如药效试验等),或指导防治,势必产生两种不良后果:一是过高地估计害虫种群总体的密度,造成人工、农药及防治费用的大量浪费,而且造成环境污染。二是过低地估计害虫种群的总体密度,
In pest control work, we must first grasp the dynamics of insect population density. However, a comprehensive survey on population density is conducted on a large scale. It is not only labor-intensive but also delays in the prevention and control of diseases. Therefore, sampling methods are generally used to estimate population values based on sample values. However, the probability distribution of the spatial structure of the insect population is not known. Only five sampling points and diagonal sampling methods are used. There is often a big error between the sample value and the actual population value, which can not even reflect the overall situation. If such data are used as a basis for carrying out research (such as efficacy tests, etc.) or guiding prevention and control, two unfortunate consequences are bound to arise: First, the overall population density of pest populations is overestimated, resulting in a great waste of man-made, pesticide and prevention costs , But also cause environmental pollution. The second is to underestimate the overall population density of pests,