柞蚕害虫蚂蚁防治药剂的室内筛选及柞园防治效果

Laboratory Selection of Insecticides for Controlling Ants Feeding on Tussah and Their Control Effects in Tussah Field

蚂蚁是柞蚕重要害虫之一,为寻找环保、高效的防治替代药剂,以食蚕蚁优势种黑褐草蚁、血红林蚁为试验对象,采用药膜法和毒饵法测定氟虫腈、辛硫磷、毒死蜱、吡虫啉、茚虫威的24 h室内毒力,结果表明,氟虫腈对黑褐草蚁的触杀及胃毒活性、对血红林蚁的胃毒活性均最高,LC50分别为0.250、1.710、0.388 mg/L,是防治食蚕蚂蚁的最佳杀虫剂。分别制备粒径1 mm和2 mm的0.010%、0.025%、0.050%、0.100%氟虫腈饵剂进行室内防效试验,结果显示,饵剂对黑褐草蚁防效受粒径影响显著,1 mm粒径的0.100%饵剂施药后48 h的防效为91.11%,72 h达100%;饵剂对血红林蚁防效则不受粒径影响,不同粒径、不同含药量饵剂防效最高均可达100%。应用粒径为1 mm的0.100%氟虫腈饵剂在柞园防治蚂蚁,施药后5 d的防效达到90%以上,较现行防治药剂1.00%辛硫磷粉剂减少90%的杀虫剂用量,有利于柞园生态环境,并且可诱集工蚁取食、搬运回巢传毒,高效杀灭巢内蚂蚁,实现省力化施药。本研究表明该氟虫腈饵剂防效高,施药简便,环境友好,适用于对柞蚕害虫蚂蚁的防治。

Ant is one of the major tussah pests. In order to find an environmental friendly and effective alternative controlling insecticide, 24 h laboratory toxicity of fipronil, phoxim, chlorpyrifos, imidacloprid and indoxacarb to Lasius niger L. and Formica sanguinea Latreille, the dominant ants feeding on tussah, were measured by drug membrane method and poison bait method. The results showed that fipronil had the highest gastric toxicity and contact toxicity to Lasius niger L. and highest gastric toxicity to Formica sanguinea Latreille, whose LC50 were 0.250 mg/L, 1.710 mg/L and 0.388 mg/L, respectively. It was proved to be the most effective insecticide against ants feeding on tussah. Baits with particle sizes of 1 mm and 2 mm were prepared at a fipronil concentration of 0.010%, 0.025%, 0.050% and 0.100%, respectively, to test their laboratory control effects. The results showed that control effects of baits on Lasius niger L. were significantly affected by the particle size. 0.100% fipronil baits with particle size of 1 mm had a control effect of 91.11% after 48 h treatment, and 100% after 72 h treatment. However, control effects of baits on Formica sanguinea Latreille were not affected by the particle size. Control effects of baits with different fipronil concentrations and different particle sizes could all reach 100%. 0.100% fipronil baits with particle size of 1 mm had a control effect of more than 90% after 5 d treatment in Tussah field. Compared with 1.00% phoxim powder, the current control insecticide, 0.100% fipronil bait could reduce 90% amount of insecticide in tussah field, which is environmental-friendly. Furthermore, the bait is labor-saving because it can effectively kill all ants in the nest by luring worker ants to feed and carry it back to the nest. In conclusion, this effective, operable and environmental-friendly fipronil bait is recommended to be used in tussah field for the control of ants feeding on tussah.