BI dropped largely from the range 5.1–55.5 in September, to the
range 0.14–13.29 during the rapid detection period (Fig. 2). The BI
value of Aedes density ofmost cities dropped to less than 5 except
that in Guangzhou city(6.70) and Haikou city(13.29), and the Aedes
densityofnearlyall cities had witnessed alarge reduction. The aver