Fumigant toxicity of essential oil from Zhumeria majdae against Callosobruchus maculatus
Abstract: Pest control in many storage systems depends on fumigation with chemical insecticides.Due to the development of insecticide resistance and risks to human health and the environment ofsynthetic compounds, the search for alternative insecticides is encouraged. Recently, there havebeen several studies on alternative substances with insecticidal activity, such as essential oils ofplants on stored insect pests. Zhumeria majdae Rech. F. and Wendelbo (Lamiaceae) is one of theseplants that have medicinal effects on human. An experiment was conducted to investigate fumiganttoxicity of the essential oil that was extracted by hydrodistillation from dry aerial parts of the plant.In this study, fumigant toxicity was tested against 1-3 days old adults of Callosobruchus maculatus(F.) with five replications at 27±1°C and 65±5% RH in dark condition. The mortality was increasedwith concentration from 37.03 to 259.25μl/l air and with exposure time from 3 to 24h. At thelowest concentration (37.03μl/l air), kills of the insects reached 20% with a 3h exposure.Concentrations from 111.11 to 259.25μl/l air and exposure time of 6h were enough to obtain morethan 50% kill of the insects. The mortalities of the insects reached 100% at concentrations higherthan 37.03μl/l air and 12h exposure time. The findings indicate the strong insecticidal activity ofZ. majdae oil and its potential role as a fumigant for stored product insects.