Geostatistical Analysis On The Temporal Patterns Of Rice Stem Borer

In order to comprehend temporal patterns of the larvae population of rice stem borer, and afford its forecast model valuable information, the data series of the population for each generation and the over-wintering larvae of Tryporyza incertulas (from 1960 to 2001) and Chilo suppressalis (from 1960 to 1990) for each generation in Dingcheng District, Changde City, Hunan Province, were analyzed with geostatistics. The results indicated that: The data series of total number about C. suppressalis, the 1st generation, the 2nd generation and the over-wintering larvae year to year displayed rather better autocorrelation and predictable, especially for the total number, which range and degree of autocorrelation were 10.3 years and 91.1%, respectively. The data series of generation to generation, the 1st generation year to year, the 3rd generation year to year and the over-wintering larvae year to year demonstrated a further long terms tendency towards seriously, especially for the over-wintering larvae. A remarkable cycle of 3 generations, one year, was observed in the population of generation to generation. The data series of total number about T. incertulas, the 1~st generation, the 3~rd generation and the over-wintering larvae year to year displayed rather better autocorrelation and predictable. The data series of generation to generation, the 2nd generation and the 4th generation year to year, however, demonstrated poor autocorrelation, especially for the 4th generation, which degree of autocorrelation was zero. The population dynamics of yellow rice borer was obviously intermittent. A remarkable cycle of 4 generations, one year, was observed in the population of generation to generation. Omitting the certain generation or interposing the over-wintering larvae only resulted in a less or slight change of autocorrelation of the whole data series generation to generation, planting system, food, climate and nature enemies, so, played more important roles in regulating the population dynamics than base number of the larvae. The basic techniques of geostatistics applied in analyzing temporal population dynamics were outlined in the last.