The city of Lawrence doesn’t spray for mosquitoes. And officials say they’re not going to start now  even with the West Nile virus looming as a threat.

The spreading virus, which had its second confirmed case in Kansas on Tuesday, has some cities and counties across the country scrambling to battle the mosquito-borne virus with chemicals.

But state health officials and biologists say that’s not the best plan of attack, at least for now.

“Massive spraying is certainly going to cause a lot of environmental damage and affect all the wrong species of mosquitoes,” said Townsend Peterson, an associate professor of ecology and evolutionary biology at Kansas University.

Only a handful of the 150 species of mosquitoes in the United States carry the West Nile virus. The ones that do breed in pools of standing water, including flower pots and bird baths.

“The much more effective way of reducing populations of the mosquitoes that cause these problems is to focus on the breeding grounds,” Peterson said.

Health officials say eliminating the pooled water, wearing long sleeves and applying bug spray containing DEET are more effective ways to battle mosquitoes.

Lisa Taylor, spokeswoman for the Kansas Department of Agriculture, said 248 government agencies in the state were licensed to spray pesticides, including both herbicides and insecticides. Taylor said it was more common for governments to spray for weeds than insects.

Lawrence and Douglas County both are certified to spray. They both use chemicals to battle weeds but not insects.

Taylor said her department, which handles the licensing, received more phone calls than normal in recent weeks from government officials asking about pesticide programs. But she said not many had signed up for new licenses.

Taylor said the Department of Agriculture wasn’t recommending cities or counties begin spraying for mosquitoes. But if they do, she said, officials should consult with residents to gauge public opinion.

“When you spray, you have considerations for people living in your city,” she said. “You have strong opinions on each side. There are questions about how effective it is and the costs incurred. It’s a tense issue.”

She also said the risks of using insecticides would need to be weighed with the risk of the West Nile virus. Less than 1 percent of people who are infected become seriously ill, and only 3 to 15 percent of those infected die.

“There has to be a very compelling reason to have an eradication program,” she said.

So far, Lawrence and Douglas County officials haven’t seen any of those compelling reasons.

“We’ve never done insecticide spraying, and we’ve not had discussions about changing it,” said County Administrator Craig Weinaug.

“I don’t know where you begin,” said City Manager Mike Wildgen. “Many of the areas that are prone to having mosquitoes are environmentally sensitive.”

Peterson noted that while the Baker Wetlands south of Lawrence are a “major breeding ground” for mosquitoes, the mosquitoes found there wouldn’t carry the West Nile virus.