鱼藤酮对红脉穗螟的控制作用研究

Study on the control effect of rotenone on Tirathaba rufivena Walker

为明确植物源杀虫剂鱼藤酮对红脉穗螟的控制水平,采用叶片浸渍法和田间喷雾法分别研究了鱼藤酮对红脉穗螟的生物活性和田间防治效果。结果表明,鱼藤酮对红脉穗螟各龄幼虫均具生物活性,其中对1龄幼虫的毒力最强,致死中浓度(LC_(50))为11.41 mg/L,随着幼虫龄期的增加,毒力逐渐减弱。鱼藤酮处理红脉穗螟卵后,可导致初孵幼虫存活率下降;鱼藤酮可阻碍红脉穗螟的化蛹和羽化,经浓度为181.12 mg/L的药液处理后,红脉穗螟的化蛹率和羽化率分别降至48.42%和24.44%;鱼藤酮还会导致红脉穗螟成虫寿命缩短和产卵量下降。喷施不同浓度的鱼藤酮后第7天,田间红脉穗螟虫口减退率和校正防效均高于50%,其中250 mg/L处理的虫口减退率和校正防效分别达80.94%和80.24%,与对照药剂啶虫脒处理效果接近。由此得出,鱼藤酮对红脉穗螟具有较好的防控潜力,可作为防治该虫的备选药剂。

To clarify the control level of the botanical insecticide rotenone against the spike moth Tirathaba rufivena,and to provide suggestions for the control of T.rufivena,leaf disc dipping and field spraying methods were used to study the biological activity and field control effects of rotenone on T.rufivena.The results showed that rotenone had bio-activity against all instar larvae of T.rufivena,especially the first instar larvae,and the median lethal concentration(LC_(50))of 11.41 mg/L.With the increase of larval instar,the toxicity decreased gradually.Meanwhile,rotenone could reduce the survival rate of newly hatched larvae after T.rufivena eggs were treated.Rotenone could disrupt the pupation and eclosion function,and the pupation rate and eclosion rate decreased to 48.42%and 24.44%after treatment with 181.12 mg/L rotenone,respectively.In addition,rotenone treatment can also shorten the adult longevity and reduce the oviposition of the adults.The field experiment showed that the population reduction rate and corrected control effect of T.rufivena were above 50%on the 7th day after being treated with rotenone at different concentrations,and the population reduction rate and corrected control effect of 250 mg/L treatment were 80.94%and 80.24%,respectively.It is concluded that rotenone has a good potential for the prevention and control of T.rufivena,and can be used as an alternative pesticide for T.rufivena control.