灰飞虱的种群特性及其与温度的关系

调查了南京地区2007～2008年灰飞虱Laodelphax striatellus(Fallén)全年的种群结构和数量动态,结合当地温度资料分析了灰飞虱虫量与温度间的关系。结果表明,灰飞虱在南京地区存在明显的春秋季高峰期及冬夏季的低谷期,且夏季的低谷出现在夏季高温时期。越冬种群以高龄若虫为主,越夏种群的年龄结构在年度间变化较大,2007年以高龄若虫为主,而2008年则以低龄若虫为主。夏季采于田间的灰飞虱若虫能在室内稻苗上连续生长发育,并且饲养一个世代后其产卵量显著提高。由此说明,南京地区灰飞虱不是以滞育形式越夏。灰飞虱若虫的耐寒性很强,在不同温度下饲养及田间越冬的不同时期,其过冷却点均在-22℃以下,且无显著差异。

Population characteristics of Laodelphax striatellus and the relationship with temperature

The population structure and dynamics of the small brown plant hopper（SBPH）,Laodelphax striatellus（Fallén）,were investigated from 2007 to 2008 in Nanjing,and the relationship between the population size of SBPH and temperature was also analyzed.The results showed that there were two population peaks in spring and autumn,respectively,and two corresponding lower amounts in summer and winter.The lower population size in summer occurred in high temperature period.High-instar nymphae were dominant in the overwintering population of SBPH.The age-distribution of the summer population varied with years.Older nymphae were dominant in the summer population in 2007,whereas it was younger nymphae in 2008.The nymphae collected from rice fields developed normally in laboratory,and the amount of laying eggs was significantly increased after reared one generation.The summer population of SBPH did not diapause in Nanjing.The cold hardiness of SBPH was strong,and the super-cooling point of the 3-4th instar nymphae was below -22℃,and there was no significant difference among reared temperatures or stages of overwintering.