沿黄稻区灰飞虱越冬种群的时空分布及抽样技术研究

2009—2010年间系统调查了河南省境内沿黄稻区灰飞虱Laodelphax striatellus Fallén越冬种群的时空动态变化,并在田间调查的基础上,运用聚集度指标法和改进的Iwao回归分析法对沿黄稻区灰飞虱越冬种群的空间分布格局、理论抽样数及序贯抽样技术进行了研究。结果表明,灰飞虱在沿黄流域主要以少量3、4龄若虫进行越冬,11月下旬进入越冬期,翌年4月上中旬为越冬代种群发生高峰期,成、若虫虫量分别为22头/m2、43头/m2;灰飞虱成虫在5月中旬开始向水稻田迁飞,迁入高峰时虫量在450头/m2以上;灰飞虱越冬代成虫在麦田中空间分布型的聚集性指标大于1,空间分布型为聚集分布型,在此基础上得出灰飞虱田间调查的理论抽样数公式:N=t2/D2(0.324/m+0.086),并且描述了灰飞虱种群序贯抽样的Iwao模型:Tn=25n±15.4n~(1/2)。研究结果为田间灰飞虱的准确抽样调查和有效防治提供了科学依据。

Spatial distribution pattern and sampling technology of small brown planthopper, Laodelphax striatellus, on wheat in the Yellow River valley of China

The population dynamics of the small brown planthopper,Laodelphax striatellus Fallén,were investigated in the Yellow River valley,Henan Province in 2009 and 2010.Based on field investigations,the spatial distribution pattern,theoretical sampling number and sequential sampling technique were determined using the methods of assembling indices and advanced Iwao regression analysis.The results show that 3rd and 4th instar nymphs were the main overwintering stages,and that the overwintering period began in the last ten-days of November.In April of the following year,the overwintering population peaked in wheat fields,with respective densities of 22/m2 and 43/m2 for adults and nymphs being recorded.Adults migrated into paddy fields in mid-May,reaching peak densities of over 450/m2.The results indicate that overwintering population in wheat fields tend to have a clustered spatial distribution.The theoretical sampling equation was N=t2/D2（0.324/m＋0.086） and the sequential sampling model was Tn=25n±15.4n~（1/2）.These results provide a scientific basis for accurate sampling and effective management of this pest.