The density of mosquitoes in downtown Shanghai?areas dropped by 46.15 percent compared to the same period last year.

However, the number of the pests rose by 134.85 percent outside the Outer Ring Road, local officials said yesterday while launching a 10-day campaign against mosquitoes.

"Doing mosquito control in early spring is very effective in restraining the pest numbers in summer, as mosquitoes who hid in warm places to survive the cold weather started to breed in April," said Jin Peiwu, vice director of Shanghai Patriotic Health Campaign Commission Office.

He said residents, enterprises and maintenance companies in residential complexes should all participate in the campaign to create a better environment.

"Although a campaign against mosquitoes earlier this year has seen results, controlling mosquitoes in the summer is still a tough task," said Leng Peien, director of the prevention department of vector control in the Shanghai Center for Disease Control and Prevention.

(Shanghai Daily April 22, 2008)