Spatial Distribution and Seasonal Fluctuation of Mosquitoes in Dhaka City

Abstract

In an entomological study conducted from March 2011 to February 2012), mosquito larvae and adults were collected from different breeding sites viz. drains, coconut barks, tree holes, lakes, artificial water containers and tubs in Dhaka city utilizing long aquatic nets and sweeping nets. Altogether, 3487 mosquitoes belonging to 13 species of 4 genera namely Culex (7), Mansonia (3), Aedes (2) and Armigeres (1) were sampled, all of which were under the family Culicidae. Among the collected mosquitoes Cx. quinquefasciatus (29%) showed the highest abundance followed by Cx. vishnui (23%), Cx. tritaeniorhynchus (14%), Cx. gelidus (6%), Cx. fatigans (5%),  Cx. fuscocephala (5%) , Cx. hutchinsoni (5%), Mn. annulifera (3%), Mn. uniformis (2%), Mn. indiana (2%), Ae. aegypti (2%), Ae. albopictus (2%) and Ar. subalbatus (1%). Maximum number of species were found in Osmani Uddan (12, n = 750) followed by Old Dhaka (11, n = 1648),Sohrawardi Uddan (9, n = 516) and Fullbaria Bus Station (7, n = 573). Irrespective of species specific distribution, mosquitoes were found abundantly in August when the rainy water creates numerous temporary breeding grounds. While species specific peak seasons were observed throughout the year.