The occurrence law and damage condition of the rice stem borer in 2001-2006 in Hanjiang rice area.

Based on the investigation materials of the rice stem borer(Chilo suppressalis Walker) in Hanjiang rice area from 2001 to 2006,the occurrence law and damage condition were analyzed in the paper.The results showed that the occurrence peak periods of the adults of the rice stem borer of the first and second generation usually were in the middle of May and last decade of July,respectively.Many peaks of adult and egg were found in the present study.The change of the number of the larvae of postwintering was more or less conformable with those of the first gene-ration and the damage rate during 2001-2003.But the change was opposite between the number of the larvae of postwintering and that of the first generation during 2004-2006.The highest damage rate occurred in 2003.The research suggested that the change of the numbers of the larvae of postwintering and the first generation was consistent with the damage rate that year,and it might be used to predict the occurrence conditions of the rice stem borer next year.