Preliminary Discussion on Relationship between Air Temperature and Occurrence of Cotton Aphis gossypii Clover in the North of Xinjiang

The discussion was firstly carried out on the relationship between the air temperature and occurrence of Aphis gossypii Glover.Aphis gossypii Glover in the north of Xinjiang harms cotton crops more seriously than that in the south of Xinjiang.Its occurrence and damage happen every three-four years in the north of Xinjiang.The relationship between difference of the variation coefficient value of air temperature and occurrence extent of Aphis gossypii Glover in different years was analyzed by using the data of occurrance of Aphis gossypit Glover during 17 years in the north of Xinjaing.The CV value was used to analyse the differentiation model,the investigation results of which basically meet the demands.The results showed:(1)The main factor of occurrence of Aphis gossypii Glover was the high air temperature in the middle ten days of July and low air temperature in the last ten-day period of June;(2)The more grealty the air temperature changes,the more possiblly Aphis gossypii Glover caused pest disaster;(3)In high air temperature from June to August,it was easily for Aphis gossypii Glover to cause great pest disaster.