Population Dynamics of Malaria Vector Mosquito Anopheles sinensis in Kyongbuk, Korea (1996-1998)

Abstract

In order to study the population dynamics of malaria vector mosquitoes, Anopheles sinensis, average numbers of female mosquito per trap-night were enumerated during the period of 3 years from 1996 to 1998. As in the general patterns of seasonal prevalence, Anopheles sinensis was first collected between late March and mid-May and was trapped in large numbers between 27th June and 19th July, showing a simple sharply pointed one-peaked curve. On the other hand, Culex pipiens pallens was found to be active thoughout almost entire season, showing irregular curves with several peaks. Culex tritaeniorhynchus first appeared between 8th June and 14th July and was trapped in large number during the period September of 5th and 18th, The number of trapped mosquitoes began to decrease from early October and a few were collected until early November in 1996 and 1998. The average number of Anopheles sinensis rapidly decreased in July as compared with average standard year, and the number was particular low in 1996. The number of Culex tritaeniorhynchus in September was 158.9 per trap-night in 1996, however, abruptly decreased to 80.8 in 1997 and then increased to 237.4 in 1998. The total number of Culex pipiens pallens abruptly increased during the 3 months from May to July in 1997, followed by a decrease. A marked decrease on mean percent index (MPI) was obtained in 1998. The above results indicate that the population density of Anopheles sinensis and Culex tritaeniorhynchus in Kyongbuk Province was increasing during the three years from 1996 to 1998, while Culex pipiens pallens abruptly decreased in 1998.