Shanghai will put in place an insect/pest emergency system next year, the Shanghai Disease Prevention and Control Center said yesterday.

The emergency system will be established to monitor insects and pests in the city and to prevent infectious diseases spread by them, the center said.

According to pest control experts, the density of Aedes mosquitoes in the city could possibly cause dengue fever.

"Although the city's mosquito density in July decreased by 30 percent than that of the previous year, the Aedes mosquito density index reached 8 percent, much higher than 3 percent, the safety level," said Leng Peien, a center director.

Leng said waste collection stands, factories, drains, parks and public greenlands are ideal mosquito breeding areas.

Besides, most man-made water scenic areas use stagnant water and the park pools are not cleaned often enough.

"Aedes mosquitoes need just a very small pool of water for breeding, so people must form the habit of changing the water and cleaning the garden pots at water sceneries," he said.

Leng believed local neighborhoods should work to arouse awareness, such as sending cleaners to sweep all parking lots, clean public greenlands and drains and renovate the water scenic areas.

At present, the city has 19 mosquito monitoring stations, which observe the changes in the mosquito density and community. "We collect data from the stations three times a month, from March to November every year," Leng revealed.

Aedes mosquitoes can spread 22 diseases, including dengue fever and Japanese encephalitis. They began settling in urban areas about 30 years ago, while earlier they lived in Asia's tropical rain forests.

(Shanghai Daily August 26, 2006)