Seasonal prevalence and host-seeking of mosquitoes in southeastern Republic of Korea

Adult mosquito surveillance was conducted at two sites at Gijang-gun, Busan southeastern area of the Korean peninsula, in 2004. The most frequently collected species at cow sheds were Anopheles sinensis sensu lato (s.l.) (83.4%), followed by Culex tritaeniorhynchus Giles (8.2%), Culex pipiens Coquillett (5.6%) and Aedes albopictus (Skuse) (2.4%). Adult populations of An. sinensis s.l. peaked during July (Trap Index, TI 1043.1), declining in August (TI 659.4) and September (TI 462.9) in 2004, while Cx. tritaeniorhynchus populations increased in August (TI 77.5) and September (TI 35.9). Adult Cx. tritaeniorhynchus was first collected in the second week of May (TI 4.0) and increased through August with two population peaks in the third week of July (TI 98.0) and the second week of August (TI 99.5). Armigeres subalbatus (Coquillett) was the most frequently collected mosquito at human-landing collections (30.4%) followed by An. sinensis s.l. (28.6%) and members of the Cx. pipiens complex (19.3%). Anopheles sinensis s.l. demonstrated two peaks of host-seeking activity at 22.00–23.00 hours and 02.00–03.00 hours in July, while in August the host-seeking peaks appeared at 22.00–23.00 hours and 03.00–04.00 hours. The black light trap collections of An. sinensis and Cx. tritaeniorhynchus demonstrated significant correlations to the ambient temperatures.