INTRODUCTION Food safety and security is a key issue now a day, especially in the circumstances of day by day rapidly increasing population of the world (Tubiello et al., 2007). Pakistan has a population of 177 million which is increasing with 2.07% growth rate. Postharvest storage of grains is facing 10 to 40% losses throughout the world (Rajashekar et al., 2010). Saving the produced grains after harvesting can be helpful to meet the food requirements of increasing population. Quality and quantity of stored commodity is directly affected by the presence of insect pests in stored food (Mondal, 1994). Insect pests can develop large populations in short period of time and contaminate the products by feeding on it, leaving their faeces, hairs, dead bodies and casted skins and produce some toxins which ultimately results in grain losses (Arlian, 2002). Earlier reports by scientists declared T. granarium (Mark et al., 2010), T. castaneum (Danahaye et al., 2007) and C. ferrugineus (Mason, 2003) as most serious and economic loss causing insects. Currently drawbacks associated with the use of conventional control strategies (synthetic insecticides) such as effect on non-target organisms (Rajendran and Sriranjini, 2008), human health concerns (Isman, 2006), environmental pollution (Ogendo et al., 2003), ozone depletion and development of insect resistance and pest resurgence (Sousa et al., 2009) have necessitated to find out some biodegradable, safe and environmental friendly sources of pesticides. Insecticides from plant sources (Essential oils) having novel mode of action against insect pests can provide an opportunity to design target specific molecules which may also be useful to overcome the problem of cross resistance (Liu et al., 2011). Numerous types of insecticidal activities of essential oils have been documented (Hasan et al., 2006). Along with feeding deterrent effects (Suthisut et al., 2011; Ko et al., 2010) essential oils may be used as insect repellent (Mishra and Tripathi, 2011), fumigant (Theou et al., 2013), contact insecticide (Gallardo et al., 2012;) and insect growth regulators (Jbilou et al., 2006). For insects, accepting any product as food is easier in the absence of feeding deterrents, than in the presence of attractants (Jermy, 1983). Extensive research work has proved the potential of plant derived essential oils as feeding inhibitors but there is not a single product commercialized to protect stored commodities (Isman, 2006). Different type of inter related complex behavioral responses (Isman, 1993), Pak. J. Agri. Sci., Vol. 54(4), 759-764; 2017 ISSN (Print) 0552-9034, ISSN (Online) 2076-0906 DOI: 10.21162/PAKJAS/17.4534 http://www.pakjas.com.pk EFFECTIVENESS OF FOUR MEDICINAL PLANT ESSENTIAL OILS AS FEEDING DETERRENT TOWARDS DIFFERENT STRAINS OF STORED GRAIN INSECT PESTS Shahzad Saleem 1,* , Mansoor ul Hasan 2 , Qurban Ali 3 , Ch. Muhammad Shahid Hanif 4 , Muhammad Wasim Sajid 1 , Sohail Akhtar 5 , Zulfiqar Ahmad 6 and Asim Mehmood 1 1 Department of Biosciences, COMSATS Institute of Information Technology, Sahiwal, Pakistan; 2 Department of Entomology, University of Agriculture, Faisalabad, Pakistan; 3 Entomology Research Institute, Ayub Agricultural Research Institute, Faisalabad, Pakistan; 4 Department of Agri. Entomology, BZ University Multan, Bahadur Campus Layyah, Pakistan; 5 Department of Agri. Entomology Islamia University Bahawalpur, Pakistan; 6 Department of Food Science and Technology, University College of Agriculture and Environmental Sciences, The Islamia University of Bahawalpur- Pakistan. * Corresponding author’s e-mail: shahzadsaleem@ciitsahiwal.edu.pk Stored products can be protected by applying essential oils as antifeeding agent. Essential oils extracted from Datura stramonium, Eucalyptus camaldulensis, Moringa oleifera and Nigella sativa were examined for feeding deterrent action against different strains of Tribolium castaneum, Trogoderma granarium and Cryptolestes ferrugineus. Test insects were allowed to feed on treated food with concentrations of 5, 10, 15 and 20% by keeping constant temperature of 30±2°C and 65±5% relative humidity. Significant reduction in weight loss of treated food as compared with untreated was observed due to reduced feeding of insects. D. stramonium was the most active antifeedant with higher feeding deterrence index (FDI, 37.37%). Feeding deterrence index was found to increase from 22.01 to 43.70% with the increase in concentrations of essential oils from 5 to 20%. Among strains, FDI (%) of essential oils was recorded highest against SWL (Sahiwal) strain of T. castaneum and T. granarium while no significant difference was observed among strains of C. ferrugineus. Essential oils possessed anti- feeding/deterrent properties and must be used as grain protectants in future. Keywords: Essential oils, phago-deterrent, anti-feedant, medicinal plants, stored grain insect pests.