LI Mei-qing, LIU Yong-quan, HUANG Yan-hui, CHEN Hui-fang, YAO Yue-xian, LIU Bin, CHEN Qing, YU Shou-yi
Chines Journal of Vector Biology and Control.
2013, 24(2):
108-111.
Objective To monitor the seasonal changes in the population density, dengue virus carriage, and dichlorvos resistance of Aedes albopictus in the urban and rural areas of Guangzhou city, China and to provide a scientific basis for the prevention and control of dengue fever. Methods The population densities of Ae. albopictus in different seasons were monitored with Aedes traps in urban Guangzhou (Baiyun district) and rural Guangzhou (a village in Conghua city). RT-PCR was used to detect the dengue virus carried by the field population of Ae. albopictus. The dichlorvos resistance of Ae. albopictus was evaluated by larva dip method. Results In the urban and rural areas of Guangzhou, there were significantly different positive indices in the four seasons. The population density of Ae. albopictus reached the peak level in summer[for urban and rural areas, mosquito and oviposition positive index (MOI)=40.54 and 38.14; mosquito-trap positive index (MI)=35.14 and 37.63; oviposition index (OI)=36.49 and 29.90]; the population density was the lowest in winter, but with MOI and MI above zero. No dengue virus was detected in Ae. albopictus. In the urban area, Ae. albopictus had low resistance to dichlorvos in spring and autumn, with a resistance index (RI) greater than 2, and it was sensitive to dichlorvos in summer, with an RI less than 2. In the rural area, Ae. albopictus had a higher RI to dichlorvos in spring and autumn than in summer, but it was sensitive to dichlorvos in all the three seasons, with an RI less than 2. Conclusion Ae. albopictus can be monitored all year round in the urban and rural areas of Guangzhou, and its population density is the highest in summer. Dengue virus is not detected in Ae. albopictus. Dichlorvos has a good performance in killing mosquito larvae, but it should be applied at the appropriate time.