Effects of Water-saving Irrigation on Community Structure and Dynamics of Arthropod Community in Paddy Fields

To investigate the effects of water-saving irrigation on community structure and dynamics of arthropod community in paddy fields,field experiments from 2012 to 2013were conducted in Gaoyou irrigation district with the traditional flooded irrigation as the control treatment.The results showed that the arthropod community in controlled irrigation fields consisted of 3classes,9orders,26 families and 41 species while the arthropod community in the flooded irrigation consisted of 3classes,9orders,31 families and 47 species.Under different irrigation modes,the orders of the sub-communities richness of arthropods from high to low were both that predatory natural enemies,pests,parasitism natural enemies and neutral insects.The Pielou evenness and Shannon-Wiener diversity index of arthropod community in controlled irrigation fields were higher than those in flooded irrigation fields,which indicated that the arthropod community in controlled irrigation fields distributed evenly and fluctuated slightly.In the controlled irrigation fields,except Nephotettix cincticeps Uhler,the numbers of Nilaparvata lugens,Sogatella furcifera and Cnaphalocrocis medinalis Guenee were lower than those in flooded irrigation fields.Controlled irrigation technology could effectively reduce pest number to prevent the outbreak of pests.