Relationship between Planting Italian Ryegrass during Winter and Hexapod Community in Rice Habitat

From Nov.2008 to Jun.2010,an ecological investigation on Hexapoda was carried out in rice habitat and non-rice habitat in Agricultural Technology Extension Station,Zhuhai,Guangdong Province.A total of 78 species of Hexapoda,which belong to 57 familes,10 orders,were obtained.The results show that Diptera and Homoptera are dominant in rice field,but only Diptera is dominant in weeds during rice growing.Diptera and Hemynoptera are dominant in Italian ryegrass field in winter.However,Hemynoptera,Thysanoptera and Diptera are dominant in weeds.Shannon-Wiener diversity index(H) is 2.30~3.20.Pielou-evenness(J) is 0.72~0.86,but the value would be changed when rice maturing.Simpson dominance index is below 0.25.There is no distinct difference on the three indices between rice growing season and winter time.Jaccard similarity index is higher in Italian ryegrass field and control field during rice growing,but higher in Italian ryegrass field and weeds in winter.