棉铃虫发生程度可以划分成若干种状态E_1、E_2、…E_i(轻发生、中等发生、重发生、大发生等),成为离散的。每一个时间单元的害虫发生只能取某一种状态,则其发生就成为时间离散、状态离散的随机时间序列。马尔科夫链是时间离散、状态离散的随机时间序列。从某一时间的某种状态,变成 The degree of occurrence of H. armigera can be divided into several states E_1, E_2, ... E_i (light, moderate, heavy, large occur, etc.) become discrete. Each time unit pest occurrence can only take a certain state, then its occurrence has become a discrete time discrete state random time series. Markov chain is a discrete time-discrete state discrete time series. From a certain state of time, into