Abstract:

Through Iwao -${\rm{\bar x}}$ regression determine, the spatial distribution on the jujube looper larvae obeys Neyman-A pattern and Poisson distribution, the basic component of the distribution is thick colony. The distribution among colony and intra-colony is random, the area of colony is equal to or less than one tree. Two sets of estimation sampling were advanced, i. e Whole-Tree Sampling and Layer Sampling, the former is advantageous when using random and chessboard sampling, and the formula of theory sampling were presented; the latter can raise sampling efficiency, and reduce sampling cost, and the estimation precision is up to the standard of production and scientific study when it estimates thick of population with lowest layer sampling replacing whole-tree sampling. Finally the sequential sampling dicision models of Iwao were presented.

Key words: Jujube looper larvae, Spatial distribution, Sampling techniclue, Layer sampling, Iwao -${\rm{\bar x}}$ regression