ecological investigation of application of pesticides in rice fields

among several pests of rice as one of the main agricultural products in iran, rice borer, chilo suppressalis is one of the most important pests of this crop. use of pesticides coincided with the occurrence of this pest in the northern region of iran in 1972. at present in order to control this pest, more than 12000 tones of pesticides granules are used annually. ecological effects of pesticides application and the use of trichograma sp. as a natural enemy, for assessing the impacts of pesticides in environments, especially on different living organisms on the plant, in irrigation water, and in 5 cm depth of surface soil, were investigated in two regions of amol, named osk. mahalleh and capik field of tashbandan. results indicated that the two treatments were not different on croploss. one the contrary, in the pesticide treatment, there was a considerable decrease in the population of living organisms, particularly, no organism was observed in 5 cm depth of surface soil. it is recommended that in order to maintain the balance of environment, the use of chemicals for controlling rice borer must be with extreme care, only in the inevitable was with the use of principles of integrated pest management.