Fumigation against dengue is ineffective, harms bees and dragonflies: Entomologists

Colombo, June 29 (Daily Mirror) - The Association of Health Entomologists has warned that mosquito fumigation alone is not an effective strategy to control dengue and could cause significant environmental damage by killing beneficial insects and contributing to insecticide resistance.

Addressing a media briefing in Colombo today, Association Chairman Najith Sumanasena said many people mistakenly believe fumigation is the primary solution to dengue control. He explained that fumigation targets only adult mosquitoes, while the mosquito's egg, larval and pupal stages remain unaffected.

He said that a single round of fumigation costs more than Rs. 20,000 and also kills beneficial insects such as bees and dragonflies, which play a vital role in pollination and maintaining ecological balance.

Sumanasena highlighted that fumigation is carried out only when scientifically necessary and should not replace source reduction measures, such as eliminating mosquito breeding sites. He further warned that excessive use of insecticides accelerates insecticide resistance, making mosquito control increasingly difficult. Citing the history of malaria control in Sri Lanka, he said authorities had been forced to switch from DDT to Malathion and later to other insecticides due to resistance.

"We scientifically educate the public and recommend fumigation only in essential situations. Continuous use of insecticides is not appropriate as mosquitoes gradually develop resistance," he said.

Meanwhile, the National Dengue Control Unit said 52,068 dengue cases and 31 dengue-related deaths have been reported across the country as of yesterday.