防治金银花尺蠖幼虫高效药剂的筛选及应用评价

Screening efficient insecticides and evaluating their applications for controlling geometrid Heterolocha jinyinhuaphaga larvae

为筛选防治金银花尺蠖Heterolocha jinyinhuaphaga Chu幼虫的高效、低残留杀虫剂,采用浸虫法和浸叶法分别测定了13种杀虫剂对金银花尺蠖幼虫的触杀毒力和胃毒毒力,筛选出高活性药剂,并对筛选的药剂进行田间防效试验及检测其在金银花中的农药残留量。毒力测定结果表明,甲维盐对金银花尺蠖2龄和4龄幼虫的毒力最高,触杀毒力LC_(ct50)分别为0.291、0.391 mg/L,胃毒毒力LC_(st50)分别为0.081、0.275 mg/L;多杀菌素、氟铃脲、氯虫苯甲酰胺药剂对金银花尺蠖幼虫也表现出较高的致毒作用。田间药效试验表明,有效成分用量2.25 g (a.i.)/hm^2的甲维盐、有效成分用量11.25 g (a.i.)/hm^2的多杀菌素对金银花尺蠖幼虫均有极好的防治效果,药后7 d防治效果分别为96.39%和93.13%,表明甲维盐和多杀菌素是防治金银花尺蠖幼虫的特效药剂。残留检测分析结果表明,有效成分用量6、12 g (a.i.)/hm^2的甲维盐喷雾处理3 d后,金银花中农药残留量分别为0.0219、0.0725 mg/kg,7 d后分别为0.0070、0.0168 mg/kg。

To screen pesticides efficient and secure for controlling Heterolocha jinyinhuaphaga Chu, the contact and stomach toxicity of 13 pesticides was tested against H. jinyinhuaphaga larvae by using the methods of leaf-dipping and body-dipping, respectively. The control efficacy of insecticides in the field and the residue dynamics of emamectin benzoate in honeysuckle were detected. The toxicity tests demonstrated that emamectin benzoate had the highest toxicity against H. jinyinhuaphaga larvae, and the values of contact toxicity LCct50 against 2nd and 4th instars were 0.291 and 0.391 mg/L, respectively, while the values of stomach toxicity LCst50 against 2nd and 4th instars were 0.081 and 0.275 mg/L, respectively. In addition, spinosad, hexaflumuron and chlorantraniliprole also exhibited strong insecticidal activity. Field experiments indicated that emamectin benzoate and spinosad had the best control efficacy against H. jinyinhuaphaga among the five insecticides, and the control efficiencies of 2.25 g (a.i.)/hm^2 emamectin benzoate and 11.25 g (a.i.)/hm^2 spinosad after seven days were 96.39% and 93.13%, respectively, which showed that emamectin benzoate and spinosad were the specific insecticides for controlling H. jinyinhuaphaga. The residues of emamectin benzoate at the dosage of 6 g (a.i.)/hm^2 were 0.0219 and 0.0070 mg/kg at the 3rd and 7th day after spraying, respectively, and 0.0725 and 0.0168 mg/kg at the dosage of 12 g (a.i.)/hm^2.