Fumigant toxicity of Eucalyptus intertexta, Eucalyptus sargentii and Eucalyptus camaldulensis against stored-product beetles

Abstract:  Three essential oils extracted from the species of the family Myrtaceae found in Kashan (centre regions of Iran) were shown to have potent fumigant toxicity against three major stored-product insects: Callosobruchus maculatus (Fab.), Sitophilus oryzae (L.) and Tribolium castaneum (Herbst). These were the essential oils from Eucalyptus intertexta R.T. Baker, Eucalyptus sargentii Maiden and Eucalyptus camaldulensis Dehnh. The mortality of 1- to 7-day-old adults of the insect pests increased with concentration from 37 to 926  μ l/l air and with exposure time from 3 to 24 h. The LC₅₀ values to the selected essential oils were between 2.55 and 3.97  μ l/l air for C. maculatus , 6.93 and 12.91  μ l/l for S. oryzae and 11.59 and 33.50  μ l/l air for T. castaneum . Fumigant effects of these essential oils were considered to warrant further research into their potential for commercial use.