Relationship between the occurrence of Mythimna separata on rice and climate factors in Menghai County.

The changes of climate factors and the number of Mythimna separata in Menghai County during 1982-2007 were analyzed,and the relationship between them was discussed.The results showed that there was certain relationship between the outbreak of M.separata and the climate conditions.There was extremely significant correlation between temperature and the number of M.separata.The temperature affected the occurrence amount of M.separata and the regression equation was y=2.691x-57.123(R2=0.110).There was no significant correlation between the relative humidity and the amount of M.separata.But the rainfall had significant relationship with the large occurrence of M.separata.