Flower visiting insects attract by the flowers colour, shape, size and fragrance as pollinator. This is a mutual relationship between flowers and insects. The present study aims to know behavioural response or ethology of flower visiting insect in relation to particular flower and/or probable atmospheric changes in two managed parks, Kolkata, India. The study areas were selected as per heavily-populated neighborhoods, nearby office buildings, nearby roads and continuous vehicular movements, human interactions as visitors. The study was carried out at 2 sampling stations viz (i) Elliot park and (ii) Agri-Horticulture Society. The flower species were selected viz. Helianthus annuus (sunflower), Petunia sp. (petunia) and Buganvilia spectabilis (Buganvilia) planting above mentioned areas because these species are more common among other species. In each flower, behavioural response or ethology of visiting insects were studied by visual observation and total 10 flowers of each species were observed randomly. The present results clearly indicate that various insects were majorly showed foraging and feeding behaviour and only mating behaviour was found in two species. This study is a preliminary assessment of flower visiting insects’ ethology but further researches are needed in relation to pollination efficiencies of flower visiting insects in the particular flower and air pollution load nearby area by using instruments. It was concluded that insect visitors are showing foraging and feeding behavior but only two species were showed mating behaviour, which may be due to the vehicular air pollution because two parks are located nearby roads and continuous vehicular movements were observed.