Insecticidal effect of imidacloprid to sucking, chewing insect pests, and predacious spiders

흡즙성 및 저작성 해충과 거미류에 대한 imidacloprid의 살충효과

  • Choi, Byung-Ryul (Division of Entomology National Institute of Agricultural Science and Technology, RDA) ;
  • Lee, Si-Woo (Division of Entomology National Institute of Agricultural Science and Technology, RDA) ;
  • Song, Yoo-Han (Department of Agricultural Biology, Gyungsang National University) ;
  • Yoo, Jai-Ki (Division of Entomology National Institute of Agricultural Science and Technology, RDA)
  • 최병렬 (농업과학기술원 작물보호부 농업해충과) ;
  • 이시우 (농업과학기술원 작물보호부 농업해충과) ;
  • 송유한 (경상대학교 농과대학 농생물학과) ;
  • 유재기 (농업과학기술원 작물보호부 농업해충과)
  • Published : 1999.12.30

Abstract

Insecticidal activities of imidacloprid to sucking type insect pests, brown planthopper (BPH, Nilaparvata lugens) and peen peach aphid (GPA Myzus persicae), to chewing type insect pests, tobacco cut worm (TCW; Spodoptera litura) and beet armyworm (BAW, Spodoptera exigua) and to spiders, Pirata subpiraticus, Pachygnata clercki and Ummeliata insecticeps, as natural enemies were investigated by several bioassay methods. $LD_{50}$ of the chemical by topical treatment to BPH was 0.015 ${\mu}g/g$(48 hrs), while $LC_{50}s$ by leaf dipping and root zone treatment were 18.1 and 21.5 ppm, respectively. There was no difference in insecticidal activities between leaf dipping and root zone treatment. Imidacloprid also showed ovicidal effect of root zone treatment and its $LC_{50}$ was 6.8ppm $LD_{50}$ (48 hrs after treatment) of imidacloprid to GPA was $0.4{\mu}g/g$ in case of topical application and $LC_{50}s$ by leaf dipping and root zone treatment were 1.9 ppm and 13.7 ppm respectively. Leaf dipping was more effective than root zone treatment in GPA At topical application $LD_{50}$ (48 hrs after treatment) of imidacloprid to chewing type insect pests, TCW and BAW, were greater than 1,492 and $312{\mu}g/g$ and $LC_{50}s$ by leaf dipping method were 4,803 and Heater than 5,000ppm respectively. This means that imidacloprid has much less effect on chewing type insect pests, TCW and BAW. $LD_{50}$(48 hrs after treatment) of imidacloprid to wandering spiders, Pirata subpiraticus, Pachygnata clercki at topical application were greater dan $2941{\mu}g/g$ and greater than $2,976{\mu}g/g$ respectively and that to webbing spider, Ummeliata insecticeps, was 357 ${\mu}g/g$. Imidacloprid showed very low toxicity to the spiders and its selective toxicity ratios between spiders and BPH were greater than 19,600, greater than 19,800 and 23,800, respectively.

Keywords

imidacloprid;Nilaparvata lugens;Myzus persicae;spiders;selective toxicity