5种药剂对枸杞棉蚜室内毒力及田间防效

为了明确5种药剂对枸杞棉蚜的适宜施药剂量,开展了室内毒力测定和田间药效试验。结果表明,1%甲维盐EC对枸杞棉蚜的毒力最高,50%噻虫嗪WG毒力最低,24 h LC50分别为2.44 mg/L和1 875.69 mg/L。5种药剂毒力大小依次为甲维盐＞啶虫脒＞吡蚜酮＞呋虫胺＞噻虫嗪。田间试验结果表明,随着施药时间的延长,5种药剂不同剂量处理的虫口数量均显著下降,施药后7 d,各处理对枸杞棉蚜防效分别达94.13%~99.84%,且各剂量处理均对枸杞树安全。5种药剂推荐使用剂量分别为:5%啶虫脒EC 25.0 mg/L以上,30%呋虫胺SC 50.0~100.0 mg/L,50%噻虫嗪WG 100.0~125.0 mg/L,25%吡蚜酮WP 83.3~125.0 mg/L,1%甲维盐EC 5.6~8.3 mg/L。

Toxicity and field control efficacy of five insecticides against Aphis gossypii

In order to explore the suitable dosage of five insecticides against Aphis gossypii Glover, toxicity bioassay and field efficacy trials were carried out. Toxicity test showed that emamectin benzoate 1% EC had the highest toxicity, with LC50 value of 2.44 mg/L after 24 h. Thiamethoxam 50% WG showed the lowest toxicity, with LC50value of 1875.69 mg/L after 24 h. The order of the toxicity of the five insecticides form high to low was emamectin benzoate, acetamiprid, pymetrozine, dinotefuran and thiamethoxam. Field efficacy trials showed that the effect of all tested insecticides increased with the extension of the time after application, the number of populations treated with different doses of five insecticides decreased significantly. The field control efficacies of five insecticides were 94.13%-99.84% seven days after application. All treatments of five insecticides were used safely in field. The recommended dosages of five insecticides were above 25.0 mg/L for acetamiprid 5% EC, 50. 0-100.0 mg/L for dinotefuran 30% SC, 100.0-125.0 mg/L for thiamethoxam 50% WG, 83.3-125.0 mg/L for pymetrozine 25% WP and 5.6-8.3 mg/L for emamectin benzoate 1% EC.