To spray or not to spray? Question for cities struggling with West Nile




Posted on July 6, 2012 at 10:16 PM

Updated Friday, Jul 6 at 10:40 PM

DALLAS - It was after 5:00 p.m. Friday, and Micheal Wheeler was still busy with his Bluetooth.

"Okay, that area is scheduled to be sprayed Monday night starting at 10 p.m.," he told someone calling to complain about mosquitoes in her neighborhood.

"Okay, thank you," he said to a worker at a Texas State lab, calling with news that more mosquitoes had tested positive for West Nile in the City of Dallas.

He took calls as he readied traps and trucks. He is in charge of Dallas' war on mosquitoes, and this summer the battle started early.

"It's about two months earlier than normal," he said.

Wheeler has quite an arsenal at his hands, but his favorite foot soldiers have wheels.

The city sends three spray trucks into neighborhoods three nights a week, spraying a chemical called Aqualeur 2020.

"The amount of chemical that comes out is very, very small," he said, explaining how the spray trucks work. "It disperses into a 300-foot swatch; about 150 feet on either side of the truck, and what it does is make contact with mosquitoes and causes the kill."

The goal is to kill adult insects.

But a couple suburbs away, there's a different approach.

"It was in the mid-[19]90s that the city stopped large-scale spraying," said Rebecca Rodriguez of the City of Arlington.

Two residents there have contracted West Nile Virus, but Rodriguez stresses there's no way to know what city they were in when they were actually bitten.

Instead of spraying, Rodriguez said workers are in neighborhoods every day doing surveillance and treating smaller pools of water to kill mosquito larvae. She said when residents report a problem, they target specific backyards, instead of whole streets.

"Spraying wider areas - entire ZIP codes - has not shown to be effective eradicating mosquitoes in a large scale," she said.

In Dallas, Wheeler said after a truck sprays a neighborhood, additional tests are done, and he said spraying has shown to be effective in cutting down on the number of West Nile positive insects.

"Even though it's not 100 percent, anything is better than nothing," he said.