Acute toxicity of kaolin and essential oils from<i>Mentha pulegium</i>and<i>Zingiber officinale</i>against different stages of<i>Callosobruchus maculatus</i>under laboratory conditions

Abstract

AbstractNaturally derived compounds such as essential oils and natural mineral are relatively cheap, non-toxic to food grains and environmentally friendly and would be suitable alternatives for currently used chemical insecticides if they have high insecticidal effectiveness. In the present study, acute toxicity of kaolin and essential oils from Mentha pulegium and Zingiber officinale were assessed on different stages of Callosobruchus maculatus at 28 ± 2 °C, 65 ± 5% R. H and dark condition. The calculated LC50 values on the egg, larvae and adult stages of C. maculatus were 1.15, 2.33 and 2.18 μl/ml air for Z. officinale and 0.07, 0.11 and 0.09 μl/ml air for M. pulegium, respectively. The result showed that M. pulegium was more effective essential oil against different stages of C. maculatus compared with the Z. officinale, and also the egg and adult stages of C. maculatus were more susceptible against essential oils compared with larval stage. The LC50 values of kaolin were 0.71 and 0.18 mg/cm2 on egg and adult of C. maculatus, respectively. The combination of tested essential oils with kaolin increased mortality of C. maculatus adults compared with their application alone. It was found that tested essential oils and kaolin had high potential in controlling different stages of C. maculatus.Keywords: Callosobruchus maculatusbioassayfumigant toxicitynatural mineralplant essential oil