natural-products-in-plant-pest-management

176 M. Kostyukovsky and E. ShaayaShaaya and Kostyukovsky, 2006). In addition, there have been repeatedindications that certain insects have developed resistance to phosphine,which is widely used today (Nakakita and Winks, 1981; Mills, 1983; Tyleret al., 1983). It should be mentioned that although effective fumigants andcontact synthesized insecticides are available, there is global concern abouttheir negative effects on non-target organisms, pest resistance and pesticideresidues (Kostyukovsky et al., 2002a; Ogendo et al., 2003). In recent years,attention has been focused on the use of botanicals as possible alternativesto toxic insecticides. Lately, there has been a growing interest in the use ofplant oils and their bioactive chemical constituents for the protection ofagriculture products due to their low mammalian toxicity and low persistencein the environment (Raja et al., 2001; Papachristos and Stamopoulos,2002). Plant oils have repellent and insecticidal (Shaaya et al., 1997;Kostyukovsky et al., 2002a; Papachristos and Stamopoulos, 2002), nematicidal(Oka et al., 2000), antifungal (Paster et al., 1995; Srivastava et al., 2009), antibacterial(Matasyoh et al., 2007), virucidal (Schuhmacher et al., 2003), antifeedantand reproduction inhibitory (Raja et al., 2001; Papachristos andStamopoulos, 2002) effects.Numerous plant species have been reported to have insecticidal propertiescapable of controlling insects (Grainge and Ahmed, 1988; Arnason et al.,1989). The toxicity of a large number of essential oils and their constituentshas been evaluated against a number of stored-product insects. Essential oilsextracted from Pogostemon heyneanus, Ocimum basilicum and Eucaluptusshowed insecticidal activities against Sitophilus oryzae, Stegobium paniceum,Tribolium castaneum and Callosobruchus chinensis (Deshpande et al., 1974;Deshpande and Tipnis, 1977). Toxic effects of the terpnenoids d-limonene,linalool and terpineol were observed on several coleopterans damaging postharvestproducts (Karr and Coats, l988; Coats et al., 1991; Weaver et al., 1991).Fumigant toxic activity and reproductive inhibition induced by a number ofessential oils and their monoterpenenoids were also evaluated against thebean weevil Acanthoscelides obtectus and the moth Sitotroga cerealella ( Klingaufet al., 1983; Regnault-Roger and Hamraoui, 1995). Our earlier investigationson the effectiveness of the essentials oils extracted from aromatic plants,showed great promise for the control of the major stored-product insects.Several of them were found to be active fumigants at low concentrationsagainst these insects (Shaaya et al., 1991, 1993, 1994).The use of edible oils as contact insecticides to protect grains, especiallylegumes, against storage insects is traditional practice in many countries inAsia and Africa. The method is convenient and inexpensive for the protectionof stored seeds in households and in small farms. Many different edibleoils have been studied as stored grain protectants against insects (Oca et al.,1978; Varma and Pandey, 1978; Pandey et al., 1981; Santos et al., 1981; Messinaand Renwick, 1983; Ivbijaro, 1984; Ivbijaro et al., 1984; Pierrard, 1986; Ahmedet al., 1988; Don Pedro, 1989; Pacheco et al., 1995).This chapter evaluates the efficacy of essential and edible oils as fumigantsand contact insecticides to suppress populations of the stored-productinsects, mainly the legume pest insect Callosobruchus maculatus. The pulse