5种药剂对椰子木蛾的室内毒力测定

椰子木蛾是2013年在中国海南新发现的棕榈科植物入侵害虫，危害严重，对中国南方热带、亚热带棕榈科植物造成严重威胁。为有效控制椰子木蛾的扩散蔓延，保护中国棕榈科植物种植业的蓬勃发展，筛选出对其具有良好防治效果的化学药剂迫在眉睫。笔者采用浸叶法，在室内使用阿维菌素等5种常用药剂对椰子木蛾3龄幼虫进行了毒力测定，分别统计24、48、72h后的椰子木蛾死亡虫数，计算供试药剂不同浓度条件下，椰子木蛾的死亡率、校正死亡率、LC50、毒力回归方程、相关系数和95%置信区间等。结果表明，5种药剂48h后对椰子木蛾的毒力大小顺序依次为毒死蜱(0.82mg/L)＞阿维菌素(0.87mg/L)＞高效氯氰菊酯(1.55mg/L)＞啶虫脒(5.74mg/L)＞吡虫啉(10.35mg/L)，阿维菌素和毒死蜱24h和48h的LC50值最小，分别为3.69、0.87mg/L和5.67、0.82mg/L，即这2种药剂对椰子织蛾毒力最高。尽管吡虫啉在72h的LC50最高，但其在24h和48h的LC50均最低，说明椰子木蛾对其敏感性较差。推荐阿维菌素和毒死蜱作为防治该虫的最佳药剂，可为椰子木蛾的田间药剂防治提供参考。

Indoor Toxicity Bioassay of 5 Insecticides to Opisina arenosella Walker

The coconut black- headed caterpillar, Opisina arenosella Walker (Lepidoptera: Coleoptera), is a kind of invasive pest discovered in palm trees in 2013 in Hainan and has caused critical harm and threat to palm trees in tropical and subtropical areas in south China. In order to protect the crop farming development of palm trees, it’ s urgent to screen out some kinds of insecticides which can control it well. The leaf dipping method was used to test the toxicities of 5 insecticides to the third instar larvae of O. arenosella Walker under laboratory conditions. The dead numbers of caterpillars after 24, 48, 72 h were counted separately. The death rate, revise death rate, LC50, the toxicity regression equations, the correlation coefficient and the 95% confidence interval were calculated under different concentrations. The results showed that the order of toxicities of 5 insecticides after 48 h was Dursban (0.82 mg/L)＞Avermectin (0.87 mg/L)＞Beta-cypermethrin (1.55 mg/L)＞Acetamiprid (5.74 mg/L)＞Imidacloprid (10.35 mg/L). LC50 of Avermectin and Dursban to the caterpillar after 24 h and 48 h were the lowest, they were 3.69, 0.87 mg/L and 5.67, 0.82 mg/L, indicating that those two insecticides had the highest toxicity to the caterpillar. Although Imicacloprid had the highest LC50 after 72 h, it was the lowest after 24, 48 h of the 5 insecticides, suggesting that the caterpillar had poor sensibility to Imicacloprid. Therefore, Avermectin and Dursban were recommended as the best pesticides for controlling the caterpillar. The results could be used to provide reference for the prevention of O. arenosella Walker in the field.