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朱红毛斑蛾(Phauda flammans Walker),隶属于鳞翅目(Lepidoptera)斑蛾科(Zygaenidae),是榕属植物(Ficus spp.)上的寡食性食叶害虫,主要危害小叶榕,垂叶榕等[1]。榕属植物是我国南方城市重要绿化树种,在城市道路,公园,小区中广泛种植,非常易于朱红毛斑蛾繁殖与扩散[2]。在厦门,自2016年首次监测到朱红毛斑蛾危害,每年的危害呈上升趋势,朱红毛斑蛾每年发生三代,常间歇性暴发危害,严重时甚至能将整株榕树叶片食光,严重影响市容市貌[3]。
在城市园林绿化的防治上,生物农药具有低毒的特性,是一种环保型农药。加大园林绿化中生物农药的使用,能有效地保护植物免受病虫害的侵扰的同时,还能保护城市生态环境,推动城市生态文明建设[4]。
通过比较四种常用生物农药,甲氨基阿维菌素苯甲酸盐(以下简称甲维盐)、苏云金杆菌、球孢白僵菌和棉铃虫核型多角体病毒对朱红毛斑蛾的毒杀效果,以期筛选出高效低毒的生物农药,为有效防治朱红毛斑蛾提供科学依据。
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甲维盐处理1 d后有明显的致死率,80000倍处理下的幼虫校正死亡率达到了60%,3 d后所有试虫死亡。各浓度处理下所有龄期的试虫麻痹作用显著,用药后基本停止进食,在体视镜下仅有少数试虫能对外界刺激能做出反应,连续观察至虫体死亡后,均未能恢复移动或进食。苏云金杆菌处理下,试虫中毒症状明显,第2 d后出现明显的体液外渗,头微伸出,身体逐渐溶解,拒食,处理3 d后,不断有试虫开始死亡,但死亡率均未超过50%,5 d后死亡率明显上升。球孢白僵菌处理下,防治效果最差,5 d后试虫未出现明显中毒症状,8 d后逐渐开始拒食,部分幼虫头部抬起,并不断有试虫死亡,处理10 d后最高死亡率仍未过90%,且仍有部分试虫未出现症状。棉铃虫核型多角体病毒处理下,5 d后开始出现症状,进食量明显减少,吐出红色体液,8 d后症状加剧,死亡率攀升,各农药处理后的症状见图1。各处理校正死亡率与时间的关系见图2。
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4种生物农药的毒力测定结果见表1。从表中可以看出,甲维盐综合毒力最高,施药1 d后LC50为10.859 mg/L,其余三种农药效果都不显著;施药5 d后药剂毒力苏云金芽孢杆菌>棉铃虫核型多角体病毒>球孢白僵菌,其中球孢白僵菌无明显药效,施药8 d后,药剂毒力棉铃虫核型多角体病毒(LC50:269.286 mg/L)>苏云金芽孢杆菌(LC50:419.436 mg/L)>球孢白僵菌(LC50:2581.854 mg/L)。施药10 d后,3种药剂毒力都显著增强,药剂毒力棉铃虫核型多角体病毒(LC50:121.140 mg/L)>苏云金芽孢杆菌(LC50:166.619 mg/L)>球孢白僵菌(LC50:233.848 mg/L)。
药剂 施药时间 毒力方程 相关系数 LC50(mg/L) 95%置信区间 甲维盐 1 d y=0.707+4.145x 1 10.859 8.77—13.445 苏云金芽孢杆菌 3 d y=3.394+0.321x 0.827 99725.017 18223.236—545736.18 5 d y=1.693+1.042x 0.992 1492.504 937.051—2377.211 8 d y=0.2+1.83x 0.975 419.436 293.136—600.153 10 d y=1.759+1.459x 0.960 166.619 96.985—286.249 球孢白僵菌 8 d y=1.899+0.909x 0.946 2581.854 1473.304—4524.506 10 d y=2.203+1.181x 0.839 233.848 152.398—358.829 棉铃虫核型多角体病毒 5 d y=0.315+1.396x 0.815 2269.372 1540.443—3343.227 8 d y=2.081+1.201x 0.886 269.286 177.952—407.499 10d y=2.022+1.429x 0.797 121.140 79.132—185.45 Table 1. Toxicity of four biological pesticides on Phauda flammans
Screening of Biological Pesticides for Controlling Phauda flammans
doi: 10.12172/202212270001
- Received Date: 2022-12-27
- Available Online: 2023-10-12
- Publish Date: 2023-12-28
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Key words:
- Phauda flammans /
- Biological control /
- Efficacy test /
- Half lethal concentration (LC50)
Abstract: In order to screen effective and low toxic biological pesticides, the laboratory efficacy test of four biological pesticides against the 3-5 instar larvae of Phauda flammans was carried out. The results showed that the four biological pesticides showed obvious toxicity to Phauda flammans, and the toxicity of abamectin-aminomethyl was the strongest. It had obvious toxicity after 1 day at 80000 times the concentration, and the LC50 was 10.859 mg/L. The LC50 of Bacillus thuringiensis, HearNPV and Beauveria bassiana were 166.619 mg/L, 121.140 mg/L and 233.848 mg/L after 10 days, 5 days and 8 days, respectively. From the perspective of the quick effect of pesticides, the content of abamectin-aminomethyl>Bacillus thuringiensis>HearNPV>Beauveria bassiana. From the perspective of the persistence of pesticides, the content of abamectin-aminomethyl>HearNPV>Bacillus thuringiensis>Beauveria bassiana. To sum up, abamectin-aminomethyl was the most appropriate pesticide with high efficiency and low toxicity for the control of Phauda flammans.