温度、湿度和覆土对小菜蛾羽化的影响

Effects of temperature, soil humidity and soil cover on Plutella xylostella (Lepidoptera: Plutellidae) pupae emergence

  • 摘要: 小菜蛾是蔬菜的重要害虫, 其非化学控制技术对蔬菜的安全生产非常重要。为了解农业措施对小菜蛾的控制作用, 在室内进行了低温、高温、淹水、土壤湿度、覆土等条件下小菜蛾蛹的羽化情况研究, 探讨温度、湿度和覆土等逆境环境对小菜蛾蛹的影响。结果表明, 在26~30 ℃的温度范围内, 小菜蛾蛹的羽化率达73%以上, 但34 ℃时羽化率下降到46.67%。小菜蛾蛹经4 ℃的低温处理后转入常温条件下, 蛹的羽化率显著下降, 且低温处理时间越长, 羽化率越低; 但随着转入常温时间的延长, 羽化率可逐渐恢复。土壤含水量对小菜蛾蛹的羽化有显著影响, 土壤含水量为10%和20%时, 羽化率分别为正常含水量(8%)的12.5%和6.2%, 含水量超过30%时, 6 d以内蛹不能羽化。淹水对小菜蛾蛹的羽化也有显著影响, 淹水12 h后移入到正常盆土表面时, 与不淹水对照相比蛹的羽化率下降25.0%; 淹水24 h后羽化率下降50.0%, 并且羽化时间推迟; 而淹水超过36 h时, 小菜蛾蛹不能羽化。覆土对小菜蛾蛹也有明显影响, 覆土1 cm厚小菜蛾蛹的羽化推迟2 d, 覆土1.5 cm以上小菜蛾蛹不能顺利羽化。研究结果显示, 适时灌水或水旱轮作、田间土壤耕翻对蔬菜地小菜蛾蛹有较好的控制效果。

     

    Abstract: Plutella xylostella is one of the main pests that affect vegetable commodity output. Current treatment by chemical pesticide spray has been considered the effective control of P. xylostella. This treatment has also developed the insecticide resistance, increased pesticide residue risks and threatened pollution-free vegetable production. In the present study, the effects of abio-chemical conditions such as temperature, soil moisture, water-logging and soil cover on P. xylostella pupae eclosion were investigated. The study aimed to elucidate agro-measure control effects, especially those of paddy/dryland rotation and soil plowing, on P. xylostella. The results showed that the rate of pupa emergence exceeded 73% at 26~30 ℃, which declined to 46.67% at 34 ℃. When treated at 4 ℃ and then grown at room temperature, the rate of pupae emergence dropped significantly. The longer the 4 ℃ pretreatment, the lower was the rate of pupae emergence. However, the emergency rate recovered to normal levels after long time of growth at room temperature. When soil moisture was 10% and 20%,the emergence rate was respectively 12.5% and 6.2% of that under normal moisture condition. No pupa emergence was observed within 6 d at soil moisture of 30%. When treated with water-logging for 12 h and 24 h and then returned to surface soil, the rate of emergence of P. xylostella pupae dropped respectively by 25.0% and 50.0% and emergency was delayed too. No pupa emergence was observed under extended treatment time of 36 h. Soil covering also had noticeable effects on P. xylostella pupa emergence. The emergence of pupae was delayed by 2 d when covered at 1 cm depth soil. Pupa did not successfully emerge when soil cover was 1.5 cm deep. The above results suggested that timely irrigation, paddy/dryland rotation and soil plowing were critical control factors of P. xylostella pupae in vegetable fields.

     

/

返回文章
返回