
Introduction: Mosquitoes are generally considered an annoyance but some species act as vectors of diseases such as malaria, lymphatic filariasis, dengue, chikungunya and Japanese encephalitis. Knowledge of the bionomics of mosquitoes, especially of disease vectors, is essential to plan appropriate vector control strategies and diseases prevention. Objectives: To Find out the Man landing densityand periodicity of Different species of Mosquitoes prevalence in Nagai district. Methodology: Two houses located close to each other in the same street have been selected for the present study with natural setup. House 1and where a human volunteer, who acted as bait, was made to lie on the floor with his usual clothing. He had been exposed to mosquito landing for five minutes of each hour of the night that is 6 pm to 6 am and the mosquitoes were collected by an electronic aspirator. House 2 also followed the same, for subsequent five minutes of the same hour. Results: Throughout the study period Culexquinquefasciatus, was found to be the predominant mosquito species in Nagapattinam area. Culexquinquefasciatus was found to have maximum man landing Density (MLD) 9 – 10 p.m. and 11pm to 12 mid night. However the Culexquinquefasciatus density ranged between 3.5 to 5 MLD throughout the night.