Epidemio-entomological survey of Japanese encephalitis in Korea.
In order to determine the seasonal prevalence and population dynamics of Culex tritaeniorhynchus in relation to the epidemics of Japanese encephalitis, and ecology of these vector mosquito in Kyungpook Province, Korea, studies were conducted during the period of 7 years from 1984 to 1990. Cx. tritaeniorhynchus first collected in June between 4th and 28th, and trapped in large numbers during the period from mid-August to early September, showed a simple sharply pointed one-peaked curve. There was a gradual decrease from mid-September, with a very small number of them collected until early October in every year. The average number of Cx. tritaeniorhynchus rapidly decreased after 1985, and the number became particularly low in 1989. The highest population density, which was observed in August during the initial three years, was found to be delayed in the following years, accompanied by a decrease in the number of mosquitoes. In the trend of nocturnal activity of Cx. tritaeniorhynchus, with oncoming darkness they become very active, gradually decreasing in activity toward mid night, but slightly increasing toward dawn. The immature stages of Cx. tritaeniorhynchus were first found in rice fields contributing to peak adult densities in mid-July. The highest average densities of Cx. tritaeniorhynchus was 14,900 per m2 on mid-August 19th. The larval Cx. tritaeniorhynchus showed high resistance levels and resistance ratios against 5 organophosphorus compounds. In the adult horizontal life table characteristics of Kyungsan colonies of Cx. tritaeniorhynchus under insectary conditions, life expectancy was 28.3 days for males and 59.8 days for females. The net reproductive rate was 7.8 and generation time was 25.6 days.
Baik
D H
DH
Department of Parasitology, School of Medicine, Keimyung University, Taegu, Korea.
Joo
C Y
CY
D000818:Animals; D003465:Culex / Q000187:drug effects / Q000382:microbiology; D004199:Disease Vectors; D004351:Drug Resistance; D004672:Encephalitis, Japanese / Q000453:epidemiology*; D006801:Humans; D007306:Insecticides / Q000494:pharmacology; D007723:Korea / Q000453:epidemiology; D008017:Life Expectancy; D009943:Organophosphorus Compounds; D011156:Population Density; D015995:Prevalence; D012621:Seasons
D007306:Insecticides; D009943:Organophosphorus Compounds