Abstract
Food spoilage of perishable and other grains are seriously proliferated during storage by stored grain insect pests under variable conditions. Resistance development in insect pests against fumigants is a serious threat to effective commercial use of fumigants in various quarantine treatments. Therefore, resistant strains of Tribolium castaneum (Herbst), Rhizopertha dominica (Fabricius) and Sitophilus oryzae (Linnaeus) were tested against phosphine and bio fumigants to check their fitness and potential following by F-1 generation. Phosphine fitness in term of mortality mean calculated at 300 ppm was minimum against weevil but highly effective against red flour beetle after 24hours while, at 400ppm showed same resistance level in all. At 500ppm, lesser grain borer (LGB) was more susceptible as compared to others as in rice weevil. Nicotiana tabacum (L.) and Calotropis procera (Aiton) oil both at 15% were most lethal to LGB, weevil and red flour beetle after 72hours following by effect of Datura stramonium (L.) and Eucalyptus camaldulensis (Dehnh) with respect to control. Similar response was noted at 10% concentrations of all plants but E. Camaldulensis (5%) was least effective against all insects after control. Resurgence response in F-1 generation in each experiment showed high multiplication rate at low concentrations and vice-versa also suppressed against N. tabacum and C. procera. Hence, developing PH3 resistance can be managed with bio-pesticides up to extant and need more work to make it applicable in field.