自然种群数量的调查是研究蝇类的(?)包括它们的季节分布、空间分布、垂直分布、以及各个蝇种的组成比例、性比例等等的基础。在研究某种蝇类与某种疾病流行的关系时,种群数量调查也是很必要的。而当前最多是用于蝇类防治效果的考核,一般分两种,一种是在使用杀虫药剂前、后测定蝇类的种群密度,进行对比,观察药剂的防治效果;另一种是在某个地区逐 The investigation of natural populations is the basis for studying the seasonal distribution, spatial distribution, vertical distribution of flies (?), Their composition ratio, sex ratio and so on. In studying the relationship between a particular fly and the prevalence of a disease, population surveys are also necessary. At present, most of them are used for the examination of the control effect of flies, generally in two kinds. One is to determine the population density of flies before and after the insecticide is used, and to compare and observe the effect of the agent for prevention and treatment. A district by the