Surveillance for Aedes albopictus in China,2006-2013

Objective To understand the population density and seasonal fluctuation of Aedes albopictus in China and provide evidence for the prevention and control of Ae. albopictus and related diseases. Methods The surveillance data of Ae. albopictus from 41 national surveillance sites during 2006-2013 were collected. The density and seasonal/annual fluctuation of Ae. albopictus in different environments, temperature zones and precipitation belts were compared. Results From 2006 to 2013, the overall average density of Ae. albopictus was 0.036 mosquito/(light hour). The difference in the density in 5 environments had statistical significance. Of five different environments, the density of Ae. albopictus in livestock yards(0.067) or in farmyards(0.046) was high with density peak in July, the density peak was observed in July and August in parks, hospitals and residential areas. The annual density was highest in 2006. The difference in the density among different temperature zones was statistical significant. The density in tropical zone was highest, followed by subtropical zone and warm temperature zone. and no Ae. albopictus was found in mid-temperature zone. Two annual density peaks were observed in July and in October in tropical zone, but only one annual density peak was observed in warm temperature zone(in August) and in semitropical zone(in July). The annual density in tropical zone increased obviously during 2010-2012. The difference in density in different precipitation belts was statistical significant. The density in the belt with annual precipitation 400-800 mm was highest(13.89), followed by that in the belts with annual precipitation 800-1600 mm and 1600 mm. No Ae. albopictus was found in the belt with annual precipitation400 mm. The annual density peak occurred in September in the belt with annual precipitation 400-800 mm, which was one month later than that in the belt with annual precipitation 800-1600 mm(August). The density peak was during June-November in the belt with annual precipitation 1600 mm The annual density was in slow increase in the belt with annual precipitation 1600 mm from 2008 to 2013. Conclusion The density of Ae. albopictus varied with environment, month, year, temperature zone and precipitation belt. It is necessary to take more specific measures for the prevention and control of Ae. albopictus and related diseases.