重庆市秀山县稻飞虱发生特点及其原因分析

重庆市秀山地区稻飞虱的发生主害种类为白背飞虱Sogatellafurcifera和褐飞虱Nilaparvatalugens,白背飞虱的危害重于褐飞虱 ;白背飞虱 1年发生 5～ 6代 ,以 4 ( 3)代为主害代 ,田间发生 2～ 3次若虫高峰 ,以第 2次为主害代峰、虫量最大 ;褐飞虱 1年发生 4～ 5代 ,以 5 ( 4 )代为主害代 ,田间发生 3～ 4次若虫高峰 ,以第 3次为主害代峰、虫量最大 ;( 3)稻飞虱重发年比例高 ,达 85 %以上 ;( 4 )白背飞虱呈逐年加重和主害期提前、褐飞虱呈逐年减轻和主害期推迟的趋势。其主要原因是 :特殊的槽谷地形、迁入虫量大、品种及栽培技术的变化、防治技术的提高和气候条件有利等。

The characteristics and causes of the occurrence of rice planthoppers in Xiushan,Chongqing

The characteristics of rice planthopper outbreaks in Xiushan, Chongqing were as follows. (1) The whitebacked planthopper Sogatella furcifera, and the brown planthopper Nilaparvata lugens, are major insect pests of rice in Xiushan. S. furcifera causes more serious damage than N.lugens. (2) S.furcifera and N.lugens have 5～6 and 4～5 generations respectively in one year with the most serious damage occurring in the 3rd and 4th generations in 2～3 and 3～4 nymphal peaks, respectively. (3) The proportion of years in which these planthoppers cause serious damage is >85%. (4) Most S.furcifera damage appears to occur in the early part of the season,whereas damage caused by N. lugens′s appears to decrease in the later part of the season. The main reasons for the severity of the damage caused by these insects are the special slot terrain, high planthopper immigration, changes in rice vaieties and cultivation methods, raising in pest control techniques and beneficial weather conditions.