The efficacy of garlic Allium sativum oil, and eucalyptus Eucalyptus globulus oil and their combinations with two organophosphorus pesticides, Dimethoate 30 % and Pestban 48% were evaluated for the control of some Piercing-Sucking insect pests associated with Faba bean Vicia faba in open field, during season 2011/2012. All of the four composites diluted to 3% before applying for four times in each spray. Samples were taken at the first, fifth, seventh and tenth days after application to determine the reduction in numbers. The results showed that, garlic oil wasthe best efficient in reducing the population of  leafhoppers and planthoppers by a mean reduction percentage of 68.09%, followed by the two chemical insecticides Dimethoate 67.90 % and Pestban 64.02 %, and Eucalyptus oil was the least in this category as 43.27 %. However in controlling aphids, also garlic surpasses again by a mean overall reduction 90.96 %, followed by Pestban 89.44 %, while eucalyptus oil came in the third rank as 80.66 % before the dimethoate which achieved the least rank in controlling aphids as 76.14 %. Furthermore experiment was conducted also to evaluate the side effects of such composites on the population fluctuations of two insect predators rife in Fababean fields, true spiders and minute pirate bug (Orius sp.). Data showed that, in compared with control, the use of natural oils preserved partly the coexist of natural enemies than the use of chemical compounds in Faba bean fields.