Effect of Essential Oils from Five Herb Plants Against Sweet Potato Weevil, Cylas formicarius (Fabricius, 1978) (Coleoptera: Apionidae)

Abstract

This study investigated the effect of five herb plants essential oils including Chinese ginger, Boesenbergia rotunda (L.) Mansf (F.Zingiberaceae), Black pepper Piper nigrum L. (F.Piperaceae), Phlai Zingiber cassumunar Roxb. (F.Zingiberaceae), Kaffir lime Citrus hystrix DC. (F.Rutaceae) and Basil Ocimum basilicum L. (F.Labiatae) against Sweet potato weevil. The mortality rate were used contact method under laboratory. Each essential oil was filtered with filter paper and transferred to petridishes. The mortality time was recorded at 10, 30, 40, 60, 90, 120 and 180 min. by stereo microscope. After 180 min., The result showed that the essential oil from basil (O. basilicum) at 20 % concentration was the most effective to kill sweet potato weevil at 84.0±8.90% follow by Kaffir lime Citrus hystrix DC., Zingiber cassumunar Roxb., Chinese ginger, Boesenbergia rotunda and Black pepper Piper nigrum L. at rate 68.0±28.6, 66.0±26.0, 20.0±18.7 and 20.0±14.1 %, respectively. The LT50 showed 110.17, 117.65, 130.98, 261.36 and 286.11 min. respectively.