Study on seasonal growth and decay of Culex tritaeniorhynchus and its influence in Sanya and Qiongzhong

OBJECTIVE To study the influence of the mosquito density,seasonal growth and decay,and environment on the epidemic encephalitis B,to provide scientific evidence for controlling Japanese B encephalitis.METHODS According to the history case of epidemic encephalitic B,we collected the mosquito by light traps,monitored the quantity of mosquito.Mosquito density(ramus/hour)= captured mosquito quantity/captured mosquito time×traps quantity.RESULTS Natural environment between the two monitor point was obviously different.Mosquito included 72.9% of Culex tritaeniorhynchus,5.4% of Culex tritaeniorhynchus,0.7% of Aedes albopictus,0.3% of Aedes aegypti,1.3% of Anopheles sinensis,and 19.4% of other mosquitos.Constituent ratio of Culex tritaeniorhynchus was 11.7% in Sanya and 3.6% in Qiongzhong.The average density was 0.15 rami/artificial hour in Sanya and 0.17 rami/artificial hour in Qiongzhong.Density of Culex tritaeniorhynchus was balanced in the year in Sanya,of which the highest density was from May to September.The higher density of Qiongzhong was from Jure to July,which was lower in other months.CONCLUSION The reason why Japanese B encephalitis case in Sanya is more than Qiongzhong is that growth reproduction cycle of Culex tritaeniorhynchus is longer and constituent ratio is higher in Sanya.The growth reproduction cycle of Culex tritaeniorhynchus is related with temperature,geographic environment,area of paddy field and the number of cultured pigs.