灌巢对红火蚁的防效评价及对蚂蚁群落的影响

利用触杀性杀虫剂灌巢防治红火蚁的试验表明,灌巢后4周,利用有效蚁丘调查法、诱集法和陷捕法评价的防治效果分瘪为100%、100%和61.54%,说明灌巢可在短期内迅速减少红火蚁的蚁丘数、降低活动工蚁数量,防治效果非常明显。试验结果还表明,在第一次灌巢13周后,以有效蚁丘调查法和诱集法获得的防效分别为100%、79.22%,说明在秋末冬初用药剂灌巢防治红火蚁的效果可维持至少3个月。试验中不同取样方法得出防效变化趋势与有效蚁丘的变化基本一致,诱集法比较适合灌巢等防治红火蚁的田间药效评价和发生监测,陷阱法仅适合蚂蚁生态学的研究。此外,还调查了灌巢后红火蚁入侵绿化地内常见蚂蚁种类及其组成。为我国红火蚁的化学防治效果的评价方法提供了科学依据。

4.5%高效氯氰菊酯EC对红火蚁的防治

采用高效氯氰菊酯EC作为防治药物,进行毒饵诱杀、混沙触杀以及蚁巢浇灌3种方法防治红火蚁的试验。结果表明:用4.5%高效氯氰菊酯EC作防治药物时,灌巢触杀的效果最佳,混沙触杀次之,毒饵诱杀最差。灌巢触杀药后第5天,蚁巢全部被杀灭,减退率高达100%。在红火蚁的化学防治实践过程中,高效氯氰菊酯EC可作为一种红火蚁的灌巢触杀剂。

Toxicity and Efficacy of Two Emulsifiable Concentrates of 2-Tridecanone against Red Imported Fire Ants

2-tridecanone is a major constitute of defensive secretion in tawny crazy ants, Nylanderia fulva that is an ant species reported to be able to displace red imported fire ants, Solenopsis invicta in the field. 2-tridecanone was proven to be toxic to S. invicta. Although 2-tridecanone is commercially available, utilization of this naturally occurring compound in fire ant management has received little attention. In this study, toxicity and efficacy of two 2-tridecanone formulations were assessed against S. invicta. Two emulsifiable concentrates were prepared using 2-tridecanone as an active ingredient, vegetable oil as a solvent and polyoxyethylene tridecyl ether as a surfactant. Piperonyl butoxide (PBO) was used as a synergist in one formulation. Both formulations showed significant toxicity in laboratory bioassays. In a field trial, at application rate of 5.28 mL/L and 14 days after mound drench treatment, 100% control was achieved for formulation with PBO and 90% control for the formulation without PBO. In conclusion, both formulations had significant efficacy against S. invicta. Due to the low mammalian toxicity of 2-tridecanone, no involvement of hazardous synthetic organic solvents, no phytotoxicity at applied concentrations, and relatively low cost, both formulations are promising alternatives to commercial insecticide products for fire ant mound drench. The outstanding efficacy of both formulations observed in this study warrants further research on their efficacy against other pest insects.

三种植物源药剂对红火蚁的防治效果评估及其对本地蚂蚁群落影响

红火蚁Solenopsis invicta Buren是一种危险性入侵害虫,可对人类健康、农林业生产、公共安全和生态系统产生严重的负面影响。目前,化学农药是防治红火蚁的主要方法。然而,大多数化学农药并不适用于有机农场、水产养殖区等生态敏感区。为筛选出用于生态敏感区红火蚁防治的药剂,本文结合室内和田间试验评估了植物源杀虫剂苦参碱Matrine、鱼藤酮Rotenone和除虫菊素Pyrethrin对红火蚁的防治效果。室内试验结果表明,苦参碱、鱼藤酮和除虫菊素对红火蚁均具有较高的毒性。田间试验表明,25.00 mg/L和12.50 mg/L苦参碱、250.00 mg/L和125 mg/L鱼藤酮、75.00 mg/L和37.50 mg/L除虫菊素灌巢处理,红火蚁蚁巢减退率分别达到100%、81.25%、87.50%、79.17%、71.73%和66.67%。然而,除25.00 mg/L苦参碱外,其他处理均导致在被灌巢的蚁巢周围短期内出现新蚁巢。灌巢处理后,处理区的蚂蚁多样性指数和均匀度指数升高,优势度指数下降。综上所述,苦参碱、鱼藤酮和除虫菊素适合灌巢处理防治红火蚁,其中0.5%苦参碱可溶性液剂能有效降低红火蚁种群数量,使得蚁巢减退率达100%,同时对本地蚂蚁群落没有负面影响,因此该商品制剂在红火蚁防治方面具有较好的开发潜力。