Distribution of overwintering mosquitoes ( D iptera: C ulicidae) in grassy fields in the R epublic of K orea, 2007–2008

Overwintering mosquitoes in a grassy field were surveyed at 13 different localities from D ecember 2007 to F ebruary 2008 in the R epublic of K orea ( ROK ). Mosquitoes were collected by putting a white colored tent on the grass, without the base, and heating the inside of the tent. A total of 784 female adults comprising seven species were collected during the study period, including 395 (45.6%) A nopheles pullus , 338 (43.2%) An. sinensis , 21 (2.7%) An. belenrae , 2 (0.3%) An. kleini , 43 (5.5%) C ulex tritaeniorhynchus , 20 (2.5%) Cx. inatomii , and 1 (0.3%) C x. pipiens complex. The mosquitoes showed different overwintering distributions by temperature zone and locality. Predominant species, the malaria vectors An. pullus and An. sinensis , showed different overwintering distributions. A nopheles pullus had a 90.9% collection rate except for Youngju and an average – 0.6°C temperature between D ecember and F ebruary. A nopheles pullus showed >50% collection rate in most regions maintained below an average of −1.4°C, and the rate of An. sinensis showed more than 50% collection rate in all regions maintained at an average above −1.1°C. Other species showed regional characteristics; An. belenrae was distributed in the northwest part of the ROK , and An. kleini was collected rarely at one locality in the middle part of ROK . C ulex tritaeniorhynchus , a Japanese encephalitis virus vector, was distributed in the southern and costal region and maintained at an above average of −1.0°C. C ulex inatomii was collected on the coastal region of the ROK .