新化合物HNPC-A8008对鳞翅目害虫的作用方式和作用特性

Characterization and mode of action of novel compound HNPC-A8008 against the lepidopterous insects

为系统评价新型吡唑类杀虫剂HNPC-A8008对鳞翅目害虫的生物活性、作用方式及环境因素对其应用效能的影响,通过叶片夹毒法、点滴法和根部内吸法测定了其胃毒活性、触杀活性和内吸活性,采用Potter喷雾法测定了温度、龄期对其生物活性的影响及对3龄粘虫幼虫的持效性,并应用浸渍法测定了其对粘虫卵的活性。结果表明,HNPC-A8008对粘虫表现出很好的胃毒毒力,且具有一定的触杀活性,但内吸活性较弱,药后24 h和72 h对粘虫触杀LD50和胃毒毒力LC50值分别为221.38μg/头和0.73 mg/L;2 000 mg/L浓度下,粘虫的内吸死亡率为56.67%;对1~4龄粘虫幼虫的的毒力分别为5.33、12.21、32.05和39.60 mg/L,对4龄的毒力最低;400 mg/L药液对粘虫卵的孵化抑制率为88.00%,初孵幼虫的死亡率为61.93%。温度对HNPC-A8008毒力发挥有显著影响,从15℃升至35℃,毒力增强了3.47倍,属正温度系数类杀虫剂。HNPC-A8008具有较长的持效期,药后0~14 d对3龄粘虫的LC50值在30.55~48.35 mg/L之间。

In order to determine the theoretical basis for further development and application,the bioactivity,mode of action and the effect of environment on HNPC-A8008 against lepidopterous insects were studied,and sandwich method,drop method and root absorption method were used to evaluate the insecticidal activity. The effects of temperature and various instars on its biological activity were measured by using Potter spraying method,and the laboratorial residual activity and activity to eggs were also tested. The results showed that HNPC-A8008 had a good stomach activity,certain contact activity and a weak systemic activity to the lepidopterous insects; the LC50 and LD50values of HNPC-A8008 against Mythimna sepatara were 0. 73 mg / L and 221. 38 μg / larva at 48 and 72 h after treatment,respectively.The mortality of M. sepatara was 56. 67% at the concentration of 2 000 mg / L. The toxicity of HNPCA8008 against larvae reduced with increasing instar. The 1st instar larvae were the most sensitive stage.The LC50 value of HNPC-A8008 against the 1st to 4th instar larvae were 5. 33,12. 21,32. 05 and 39. 60 mg / L,respectively. The suppression rate of hatching was 88. 00% and the mortality of larvae was61. 93% at 400 mg / L drug treatment. Temperature had a significant effect on HNPC-A8008,and the toxicity of HNPC-A8008 to the larvae of M. sepatara increased by 3. 47 folds when temperature increased from 15 to 35 ℃,indicating that it is an insecticide with a positive temperature coefcient. HNPC-A8008 also had a very good residual effect. The LC50 value of HNPC-A8008 against the 3rd instar larvae was between 30. 55 mg / L and 48. 35 mg / L from the beginning to 14 th day after treatment.