The results from systematical investigation in field indicated that the migration regularity of the population of rice planthoppers Nilaparvata lugens and Sogatella furcifera kept temporal consistency in different resistant rice varieties.The N.lugens populations were different between two sensitive rice growth stages before northward migration,and aggregated in boot stage at the end of June and migrated to mid-tillering stage in early and middle July,however the maximal population of southward migration on...