CO2浓度升高对草地贪夜蛾生长发育的直接影响

Direct effects of elevated CO2 concentration on development of fall armyworm Spodoptera frugiperda（J.E.Smith）

草地贪夜蛾自2019年1月入侵云南以来,已迅速扩散至我国20个省,对我国的农业生产造成了极大危害。本研究通过在两种CO2浓度(400ppm和800ppm)下用离体玉米叶片饲养草地贪夜蛾,分析比较了CO2浓度升高对草地贪夜蛾生长发育和繁殖力的直接影响。结果表明:在800ppmCO2浓度下,草地贪夜蛾各虫态发育历期均长于400ppmCO2浓度下的发育历期;其中,1龄、6龄幼虫发育历期,幼虫总发育历期和蛹期在两种CO2浓度下差异均达到极显著水平(P<0.01)。此外,相同龄期草地贪夜蛾幼虫体重在两个CO2浓度之间差异不显著,但蛹重存在极显著性差异,分别为198.82±3.45mg(400ppm)和245.89±4.18mg(800ppm)(P<0.01);高CO2浓度下雌虫的产卵期显著长于正常CO2浓度下的产卵期,分别为2.4±0.8d(400ppm)和6.0±0.9d(800ppm),高CO2浓度下平均单雌产卵量是正常CO2浓度下的2.43倍,差异显著(P<0.05)。研究结果为预测草地贪夜蛾未来的发生趋势提供了理论依据。

The fall armyworm (FAW) Spodoptera frugiperda was first detected in Yunnan, China, in January 2019, and spread to 20 provinces, which caused dramatic damage to agriculture production in China. The current research raised FAW under two CO 2 concentrations (400 ppm & 800 ppm)using fresh corn leaves, and the direct effects of elevated CO 2 concentration on developmental time, weight and fecundity were analyzed. Result showed that the developmental time of FAW was longer under high CO 2 concentration than that under normal CO 2 concentration: the developmental time of 1 st instar and 6 th instar larvae was significantly longer under high CO 2 concentration, and so as developmental time of larvae, pupae and mean generation time ( P <0.01). There was no significant difference of larvae weight between two CO 2 concentrations at the same instar, however, pupae weight was significantly different, which were 198.82±3.45 mg (400 ppm) and 245.89±4.18 mg (800 ppm) respectively ( P <0.01). Female oviposition period was 66.0±0.9 d under 800 ppm, which was significantly higher than that under 400 ppm (2.4±0.8 d), and female fecundity under 800 ppm was 2.43 times higher than that of 400 ppm ( P <0.05). The result provides theoretic evidence for FAW population prediction.