【摘要】 褐飞虱已成为我国当前水稻生产上的重要害虫。初步查明,褐飞虱在我国过冬地区的分布大体以一月份12℃等温线为北限,由于各年冬季气温高低的不同,越冬北界摆动于北纬21—25°之间;冬季田间有无稻苗存活,是能否在当地过冬的生物指标。按越冬分市可划分为:1.终年繁殖区:北纬19°以南的海南岛南端;2·少量越冬区:海南岛中部至北回归线之间;3·不能越各区:常年在北回归线以北无越冬。 褐飞虱常年不能越冬的广大稻区内,每年春夏季发生的虫源,经近年来多方面研究,证明是自南向北远距离迁飞而来。 根据褐飞虱在我国的越冬分布,南、北各稻区发生的代数和季节性种群消长规律,试将我国东半部划分为六个发生区:即终年繁殖区、少量越冬区、南岭6、7代区、岭北5代区、沿江4代区、沿淮2—3代区。 近三年的研究,特别是1977年在我国各稻区设点进行迁飞跟踪观察表明,春、夏季向北迁飞有五个过程,秋季又有三次向南回迁。褐飞虱在我国东半部的迁飞途径大体是:4月中、下旬—5月上旬第一次“北迁”,是由19°N以南终年繁殖区迁到两广南部20—23°N之间;5月中、下旬—6月上旬第二次“北迁”,是由海南岛中部往北及中南半岛同纬度地区迁到我国两广南部和南岭地区;6月中、下旬—7月初第三次“北迁”,是由两广南部稻区主迁到南岭以北更多还原

【Abstract】 In recent years the brown planthopper Nilaparvata lugens Stal has hecome a serious pest of growing rice in China.The observations of last several years showed that this insect can only overwinter in South China where growing rice plants are present in winter.Detailed analysis indicated that the limiting average temperature in January for its survival is about 12℃ or the extreme minimum temperature in winter not below 2° to 3℃.The northern boundary of its overwintering sites was along the Tropic of Cancer in a majority of years,but due to the yearly biases of the meteorological factors it may move between lat.21° and 25°N.Based on the time of its simultaneous sudden appearance in wide areas from spring to autumn five northward migrations including 11 peaks and three southward migrations including 7 peaks may be ascertained in 1977.It was found that mass migrations of the maeropterous adults synchronized with the approaching maturity of rice in their original infesting areas.The ovaries of most maeropterous exodus females remained at the first developmental stage or early second stage in these areas.During the migration the ovaries reached the second developmental stage as shown by dissecting the females caught in alpine nets.The numbers of the insects caught by the light traps in the emigration areas declined rapidly during the migration time whereas in the immigration areas the catches increased rapidly.The emigration and immigration areas may cover quite wide ranges,and as judged with the population densities the immigration areas can be categorized into main and minor groups.The migrations showed close correlation with the synoptic weather conditions.Continual SW winds favoured northward migrations in spring and summer while NE winds favoured southward migrations in autumn.Seasonal variations in atmospheric currents were of great importance in inducing the migrations.Based on our observations on the occurrence of this insect in various regions we propose six outbreak regions as follows:1.year round breeding and infesting regions,south to lat.19°N,with 13 generations a year,2.minor overwintering regions,from lat.19° to 24°N,with 8 to 11 generations a year,3.Nanling regions,from lat.24° to 26°N,with 6 to 7 generations a year,4.north to Nanling regions,from lat.26° to 28°N,with 5 generations a year,5.regions along Yangtze River,from lat.28° to 32°N,with 4 to 5 generations a year,and 6.regions along the Huai River,from lat.31° to 35°N,with 2 to 3 generations a year.A schematic diagram is proposed to show the routes of the seasonal migrations of the planthopper.更多还原