In India, fruit flies have been identified as one of the ten most serious problems of agriculture because of their polyphagous nature and the huge economic loss it causes to the fruits and vegetables (2.5 to 100%). Study was carried to determine the population dynamics of fruit flies (Bactrocera dorsalis and Bactrocera zonata) and establish the correlation with abiotic factors in guava and citrus fruits crops in two agro ecological zones of North West India. Fruit flies population was recorded by installation of pheromone traps in different fruit crop ecosystems during the fruiting season of this zone. The data of trap catches of both the locations was correlated with the significantly influencing abiotic parameters. The peak fruit fly incidence varied between 31st to 34th standard weeks in guava ecosystem at both the locations. In citrus ecosystem, the incidence was highest during 35th and 39th standard weeks coinciding with the ripening of the fruits. At both the locations, trap catches of guava ecosystem were positively correlated with all the weather parameters, while under citrus ecosystem minimum temperature and rainfall showed negative correlation, but relative humidity was positively correlated. Information may be utilized in targeting suitable pest management techniques for respective zones.