The distributions and abundance of mosquitoes were examined in 2012 in rice-field areas in north-eastern Japan where the tsunami caused by the Great East Japan Earthquake in March 2011 destroyed man-made as well as natural environments completely. Three study sites were selected for the mosquito study; southern Miyagi Prefecture, and northern and southern Fukushima Prefecture. Monthly mosquito collections were conducted by CO2 traps and the density was compared between the “Tsunami” area and “No tsunami” area. A total of 8,079 adults of 12 species in 7 genera were collected and Culex pipiens group, Cx. inatomii, and Aedes albopictus were dominant. The difference in adult density between the Tsunami area and No tsunami area was still significant for the dominant mosquitoes in 2012, the 2nd year after the tsunami disaster. The adult density in 2012 was significantly lower than that in the previous year; however, Cx. pipiens group and Cx. inatomii reached a high density of 100 and 30 females per trap per day, respectively, in July or August 2012, indicating that the outbreaks of these mosquitoes occurred again in tsunami areas in 2012. Mosquito larvae were found in 22 to 57% of water bodies examined in the tsunami area.
