七种杀虫剂对暗黑鳃金龟成虫和幼虫的毒力及田间防控效果

为筛选防治暗黑鳃金龟Holotrichia parallela的有效药剂,用浸虫法测定了7种药剂对暗黑鳃金龟幼虫的毒力,分别采用浸虫法、浸叶法、药膜法测定了7种药剂对其成虫的毒力,并通过大田试验作了进一步验证。浸虫法测得高效氯氟氰菊酯对成虫的毒力最高,LC₅₀值为1.38 mg/L;浸叶法测得辛硫磷毒力最高,为42.05 mg/L;药膜法测得毒死蜱毒力最高,为18.51 mg/L。其中,高效氯氟氰菊酯毒力值变化最大,浸虫法毒力是浸叶法毒力的61.86倍;氯虫苯甲酰胺、氟虫腈在3种生测方法中毒力相当,但均较低。丁硫克百威对暗黑鳃金龟幼虫的毒力最高,LC₅₀值为7.29 mg/L。田间试验结果显示,35%辛硫磷微囊悬浮剂4 500 g/hm²(有效成分,余同)防效达80.66%,对花生的保果、增产幅度分别为77.90%、17.56%;30%毒死蜱微囊悬浮剂2 250 g/hm²、20%丁硫克百威乳油3 000 g/hm²与辛硫磷防效相当,且显著高于其它药剂。因此,选用以上药剂于7月中下旬花生封垄前田间灌墩可以有效减轻暗黑鳃金龟为害。

Toxicity and control effect of seven insecticides to Holotrichia parallela

Toxicity of seven insecticides to the white grub, Holotrichia parallela, was determined with insect-dipping test, and toxicity of seven insecticides to adults of H.parallela was also determined using insect-dipping test, glass-vial bioassay and leaf-dipping method to select effective insecticide, and field experiment was done at the same time. The result showed that the highest toxicity to the adult belong to cyhalothrin in insect-dipping treatment, phoxim with leaf-dipping method, and chlorpyrifos with glass-vial bioassay. Toxicity of cyhalothrin was significantly changed in different methods, and the relative virulence multiples of cyhalothrin with insect-dipping test was 61.86 times to that of leaf-dipping; chlorantraniliprole and fipronil had no significant change, but they had the lowest toxicities in every bioassay test. Carbosulfan had the highest toxicity to the white grub, and the LC₅₀ was 7.29 mg/L. The field experiment showed, in the seven different pesticides, the control effect against white grub was 80.66% when using 35% phoxim microcapsule suspension 4 500 g/hm², the protection effect on peanut was 77.90%, the yield of peanut was increased by 17.56%. There were no significant difference compared with that of 30% chlorpyrifos aqueous capsule suspension 2 250 g/hm² and 20% carbosulfan emulsifiable concentrate 3 000 g/hm², but significantly higher than other pesticides. In the middle of July, one of the three inse- cticides can be chosen as the ideal pesticide against H.parallela in peanut field.