Cotton is most important fiber crop of Pakistan. Cotton contributes 1.6% in GDP of Pakistan. The sucking and chewing insect pests attack on the cotton and cause yield reduction. Among sucking pests, Thrips tabaci is the major one. The study was conducted to observe the ecological impacts of PB ropes on population dynamics of T. tabaci as well as beneficial fauna on cotton. The study was conducted at MNS University of Agriculture Multan at experimental farm Multan on an area of 27 acres. The experimental plot was divided into 3 blocks and each block consisted of 3 acres. Cotton variety NIAB-878 was cultivated as test crop and data was recorded on weekly bases from 20 random selected plants in each sub-plot for sucking insect pests and 10 plants for beneficial insects. The results revealed that population of T. tabaci remained significantly lower in double application of PB-ropes in a season treated plots as compared to treatment i.e., one application of PB-ropes + insecticides, while higher population was recorded in untreated block, managed through use of pesticides. The study resulted that all recorded green lacewing and Geocoris were showed negative correlation with T. tabaci and kept its population at minimum level as compared with control.