鱼藤酮与氟虫腈混用增效对黄曲条跳甲的控制作用

Synergism of rotenone mixed with fipronil and their effectiveness to Phyllotreta striolata

黄曲条跳甲是蔬菜重要害虫，生产实践中亟需高效安全的防治药剂。采用浸渍法从有机磷、拟除虫菊酯、新型杂环、植物源类等共16种常用杀虫剂中筛选出对黄曲条跳甲成虫触杀活性较高的鱼藤酮和氟虫腈，两者以3：2混用时，处理后24h对黄曲条跳甲成虫的LC50为9．60μg／mL，共毒系数为230．14，增效作用明显。以此配方配制成6％鱼氟乳油，质量稳定合格，触杀活性强，作用迅速，以0．45μg/cm^2和0．75μg/cm^2剂量药膜法处理后48h校正死亡率分别为83．72％和98．70％；以50μg/mL处理试虫致死中时LT50为10．12min。鱼氟乳油处理显著增强对黄曲条跳甲成虫呼吸的抑制作用可能是其主要增效机制。6％鱼氟乳油450mL／hm^2处理后10天内，田间虫口减退率为72％～96％．防治效果为90％以上。

Studies on the synergism of rotenone mixed with fipronil against the striped flea beetle, Phillotreta striolata （ Fab. ）, were carried out after the investigation of the contact poisoning to the adults of P. striolata with 16 kinds of insecticides, including organophosphorus, pyrethroid, heterocyclic and botanical insecticides. The results in dip tests showed that the value of LC50 was 9.60μg/mL and the cotoxicity coefficient was 230.14 after treatment 24 h when ratio of rotenone, fipronil was 3 ： 2. Based on these results, 6% rotenone-fipronil EC was formulated and all of its technical indexes accorded with quality level of pesticide. The adjust mortalities were 83.70% and 98.70% when the treatment dosages were 0.45μg/cm^2 and 0.75 μg/cm^2 in toxic membrane test after treatment 48 h, respectively. The value of LT50 was only 10.12 min when the adults of P. striolata is treated with 50μg/mL in topical application test. The rotenone-fipronil EC could significantly enhanced the breath inhibition to tested adults, which may be the main synergism mechanism. The results of field plot test demonstrated that the amount of adults of P. striolata was reduced by 72%- 96% and effectiveness was over 90% when the rotenone-fipronil EC was sprayed with 450 mL/hm^2. The rotenone-fipronil EC was worthy to be popularized.