‘Bacteria, dragonflies beat insecticide’

Scientists say insecticide spray boosting mosquito’s immune system.

LAHORE:

Biological agents like larvae-eating bacteria and dragonflies would be a far more effective check on the mosquito population in the province than insecticide spraying, according to government entomologists tasked with identifying major dengue mosquito breeding sites in the city.

The team of entomologists inspected Shahdara on Monday and found several ponds filled with dengue mosquito larvae. “These ponds appear not to have been sprayed,” said one scientist. “If they were it didn’t kill the larvae, it only pushed the mosquitoes away for a few days.”

Another team member added: “We are stunned to see so many larvae and mosquitoes here. They could affect thousands of people if left unchecked.”

A senior entomologist said that they believed that the insecticide spray was merely strengthening the mosquito’s immune system and the government should alter its strategy to control the menace.

“There is a bacteria named Bacillus Thuringiensis Israelensis that is known for eating mosquito larvae. These bacteria can be produced in laboratories and introduced into water bodies. They would reduce the mosquito population to a great extent,” he said.

He said that dragonflies, the mosquito’s natural predator, were another effective check, as a single adult dragonfly ate hundreds of mosquitoes every day.

“In the villages these insects are very important otherwise the farmers wouldn’t be able to till their fields due to all the mosquitoes,” said another entomologist. However, dragonflies need a pollution-free environment to thrive and that certainly was not available in Lahore, he said.

The entomologists said they were compiling their recommendations and would present them to the authorities concerned. “If we don’t adopt these controls dengue is going to affect an even larger population in the days to come,” said one team member.

Another entomologist who inspected graveyards on Monday said that they were among the top breeding places in the city because people left pots of water on the graves of their loved ones where mosquitoes laid eggs.

Death toll

Meanwhile, 368 new cases of dengue were reported in Punjab in the last 24 hours, according to the Health Department. A total of 105 people have been confirmed dead due to the virus, including 96 in Lahore.

(Read: Death by dengue)

Also on Monday, Chief Minister Shahbaz Sharif visited Government Model Girls High School, Model Town and Boys Degree College Shalimar, recently reopened after a 10-day closure so they could all be fumigated. The chief minister, who was accompanied by other politicians and officials, was promoting the government’s ‘Qadam badhao, Dengue mukao’ campaign to raise awareness of preventive measures against the disease.

Published in The Express Tribune, September 27^th, 2011.