39 Internet Journal of Food Safety, Vol.10, 2008, p.39-49 Copyright© 2008, Food Safety Information Publishing Insecticidal Activity Aegle marmelos (L.) Correa Essential Oil Against Four Stored Grain Insect Pests Rajesh Kumar 1 , Ashok Kumar 1 , Chandra Shekhar Prasa1 1 , Nawal Kishore Dubey 1 * and Raju Samant 2 1 Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, India 2 Deaprtment of Entomology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, India *Corresponding author. mailing address: Centre of Advanced Study in Botany, Faculty of Science, Banaras Hindu University, Varanasi- 221005, India. Phone: 91- 542-2307146, 2307147, Fax: 91-542-268174, E- mail: nkdubeybhu@gmail.com. Introduction Cereals and pulses have great biological and nutritional value in developing countries, are lost upto 20-60 per cent by storage insect pests during storage (Arthur and Throne 2003; Babu et al. 2003; Shaaya et al. 1997). Post harvest deterioration causes economic losses due to obvious decay and adverse changes in the odour, taste, appearance and nutrition value (Phillips and Burkholder 1984; Mondal and Port 1994; Arlian et al. 1996). In addition, the arthropods transfer bacteria and microscopic fungi of pathogen importance on stick on their bodies or disseminate them via faeces (Wilbur and Mills 1978, Hubert et al. 2004). During recent years considerable attention has been paid towards exploitation of plant materials in protection of food commodities from insect infestations. Extracts of some plant species viz. Lantana camara (Saxena et al. 1992), Illicium verum (Ho et al. 1995), Tithonia diversifolia (Adedire and Akinneye, 2004) have been reported to possess strong insecticidal activity against different storage insects. Plant derived products namely, azadirachtin from Azadirachta indica, pyrethrin from Chrysanthemum cinerariaefolium, carvone from Carum carvi and allyl isothiocynate from mustard and horseradish oil have been received global attention due to their pesticidal properties and potential to protect several food commodities (Hartmans et al. 1995; Ward 1998; Varma and Dubey 1999; Athanassiou et al. 2005). Essential oils produced by different plant genera have been reported to be biologically active and are endowed with insecticidal, antimicrobial and bio regulatory properties (Mishra and Dubey 1994; Varma and Dubey 1999; Dubey et al. 2004; Holley and Patel 2005). The volatility and biodegradability of flavour compounds of angiosperm will be advantageous if they are developed as pesticide insecticide (French 1985). There may be least chance of residual toxicity by treatment of food commodities with volatile substances of higher plant origin. Aegle marmelos (L.) Correa (Rutaceae), commonly known as Bael, is a sacred tree for Hindu Religon, native to northern India, but is found widely throughout the Abstract: Experiments were carried out to determine the potential of using essential oil from leaves of Aegle marmelos to control insect infestation of stored gram from Callosobruchus chinensis (L.) (Bruchidae) and wheat from Rhyzopertha dominica (F.) (Bostrychidae), Sitophilus oryzae (L.) (Curculionidae) and Tribolium castaneum (Herbst) (Tenebrionidae). After introducing the test insects, stored gram and wheat samples were fumigated with essential oil of Aegle marmelos at 500 μg/mL (ppm). The oil significantly enhanced feeding deterrence in insects and reduced the grain damage as well as weight loss in fumigated gram and wheat samples infested with all insects except T. castaneum. The essential oil at different doses significantly reduced oviposition and adult emergence of C. chinensis in treated cowpea seeds. The oil protected stored gram from C. chinensis and wheat from R. dominica and S. oryzae for two years. Limonene (88 %) was found to be the major component in the oil through GC-MS analysis. Regression analysis of data on individuals in treated cowpea confirmed that significant reduction of oviposition and adult emergence of C. chinensis decreased with increase in doses. The findings emphasize the efficacy of A. marmelos oil as fumigant against insect infestations of stored grains and strengthen the possibility of using it as an alternative to synthetic chemicals for preserving stored grains. Key words: Aegle marmelos, Callosobruchus chinensis, Rhyzopertha dominica, Sitophilus oryzae, Tribolium castaneum, oviposition