高CO_2浓度和施氮量对褐飞虱生长发育及繁殖的影响

Effects of elevated CO_2 and nitrogen fertilization on development and reproduction of the rice planthopper Nilaparvata lugens

迄今针对CO2浓度和氮肥对刺吸式口器昆虫的影响研究出现截然不同的结论。本研究旨在检验假说:CO2浓度升高和氮肥增加将不利于褐飞虱的个体发育和生殖。利用智能人工气候箱设置CO2水平(390和780μL.L-1)和氮肥水平(20、40、80、120和160 mg.L-1),观察其对褐飞虱发育和繁殖的影响。结果表明:CO2浓度和氮肥量对褐飞虱卵和若虫历期、若虫存活率、雌虫生殖力以及雌虫寿命等生物学特性具有显著的影响。与当前CO2浓度(390μL.L-1)相比,在CO2浓度升高处理下褐飞虱生长和生殖随氮肥量的增加表现为:1)卵历期显著延长;2)若虫存活率降低,从低氮肥水平(20 mg.L-1)下的77.5%降低到高氮肥水平(160 mg.L-1)下的49.3%;3)雌虫生殖力下降,单雌产卵量从低氮肥水平(20 mg.L-1)下的360.9粒减少到高氮肥水平(160 mg.L-1)下的195.4粒;4)雌成虫寿命缩短,从低氮肥水平(20 mg.L-1)下的26.8 d缩短到高氮肥水平(160 mg.L-1)下的16.3 d。研究结果支持拟检验的假说。

Previous studies of the effects of elevated CO2 and nitrogen fertilization on sap-sucking phytophagous insects yield contrasting conclusions.The present study was to test the hypothesis that elevated CO2 and increasing nitrogen fertilization might have negative impacts on the rice planthopper,Nilaparvata lugens in development and reproduction.The CO2 concentration was treated as the ambient（390 μL·L-1）and elevated levels（780 μL·L-1）,and the nitrogen fertilization as the levels of 20,40,80,120,and 160 mg·L-1 in incubators.Rice plants were potted and inoculated with neonate nymphs that were followed by the observation of development and fecundity.The results showed that CO2 and nitrogen fertilization treatments had significant influence on egg and nymph development time,nymph survival,fecundity,and female longevity.The development and reproduction of N.lugens were adversely affected by increasing nitrogen fertilization under the elevated CO2 compared to the ambient CO2,as indicated by：1）extended developmental time of eggs,2）decreased survival rate of nymphs from 77.5% under the low N fertilization level（20 mg·L-1）to 49.3% under the high N level（160 mg· L-1）,3）decreased fecundity from 360.9 eggs per female under 20 mg·L-1 to 195.4 eggs per female under 160 mg·L-1 in N fertilization,and 4）reduced female longevity from 26.8 days at the low N level to 16.3 days at the high N level.The results of this study confirmed the hypothesis.