防治桃小食心虫越冬幼虫的有效药剂及其降解动态

研究树下土表施药防治桃小食心虫越冬幼虫的取代药剂。用毒土法测定了分属4类的13种药剂对桃小食心虫越冬幼虫的触杀毒力,其结果以毒死蜱、三唑磷、高效氯氟氰菊酯、甲基对硫磷和辛硫磷毒力较高,LC_(90)值依次为18．38、22．48、35．95、47．63及49．57 mg·kg~(-1),甲氰菊酯、丙溴磷、阿维菌素、甲胺基阿维菌素、氰戊菊酯、马拉硫磷、丙硫克百威和丁硫克百威LC_(90)值处于77．11～205．86mg·kg~(-1)之间。用高效液相色谱法测定了毒力较高的毒死蜱、三唑磷、高效氯氟氰菊酯以及阿维菌素在土壤中的降解动态,半衰期分别为8．28、11．37、10．17及19．70天。欲达30天的有效控制期,按LC_(90)值计算,这4种药剂在土壤中的初施浓度应分别为226．36、139．90、278．03及346．81mg·kg~(-1)。从药剂毒力、降解速率、相同控制期所需剂量及应用成本综合评价,毒死蜱、三唑磷具有较高的应用价值。

The efficiency and degradation dynamics of insecticides for controlling the overwintering larvae of Carposina niponensis Walsingham

The substitutional insecticides using in soil under trees for controlling the overwintering larvae of Carposina niponensis Walsingham were studied. The toxicities of thirteen insecticides to overwintering larvae of Carposina niponensis Walsingham were tested with the method of toxic soil.The results showed that chlorpyrifos,triazophos,lambda-cyhalothrin,parathion-methyl and phoxim had high toxicity to the larvae. The LC₉₀ value were 18.38, 22.48, 35.95, 47.63 and 49.57mg·kg^-1,respectively,and the LC₉₀ values of the other eight pesticides (including fenpropathrin,profenophos,abamectin,emamection benaoate, fenvalerate, malathion, benfuracarb and carbosulfan) were between 77.11-205.86mg·kg^-1.The half-lives of chlorpyrifos, triazophos, lambda-cyhalothrin and abamectin were determined by high-performance liquid chromatograph, and the half-lives were 8.28, 11.37, 10.17 and 19.70d, respectively.According to the LC₉₀ value, if a 30-day control period was expected, the applying concentrations of the four pesticides would be 226.36, 139.90, 278.03 and 346.81mg·kg^-1 , respectively.Considering the toxicities, degradating velocity, the dose for the same control period and applied cost, chlorpyrifos and triazophos had higher values in controlling the overwintering larvae of Carposina niponensis Walsingham by applying them in the soil.