Time to manage mosquitoes

Draining standing water halts breeding, prevents virus spread

By Dan Shaw
Journal & Courier
Thursday, May 25, 2006

Mosquito tips Here's what the Tippecanoe County Health Department suggests people do to prevent mosquitoes from hatching in their backyards and getting into their homes: Make sure doors and windows have tight-fitting screens. Remove or empty water in tires, tin cans, buckets, drums or other places where water might collect. Check clogged gutters and flat roofs for poor drainage. Clean and chlorinate swimming pools. If not in use, keep pools empty and covered. Change birdbath water and empty plant pots or drip trays at least once a week. Empty pet bowls daily. Keep weeds and tall grass cut short. Encourage and help your neighbors eliminate breeding sites on their properties. Shape ground surface around your home to promote good runoff. To report an infestation of mosquitoes, call the county health department at 423-9221, ext. 2.

Forrest Feuer says he doesn't worry about contracting the West Nile virus.

"It's about as scary as the bird flu," said the Purdue University student while walking outside West Lafayette's Wabash Landing on Wednesday. "It doesn't exist until I get it."

Still, members of the Tippecanoe County Health Department hope to make him and others understand what can be done to fight the virus by eliminating the breeding habitats of mosquitoes, which can transmit West Nile to humans.

Feuer said he hasn't noticed many of the insects yet.

"Only at the Celery Bog, when I go walking at night," he said. "There was literally a swarm of them so large it looked like a black cloud going through the air."

But with the recent days of rain, the time is ripe for a crop of mosquitoes, said R.J. Beck, a water and vector control specialist at the county health department.

"With the rising temperatures, the maturations -- from egg to larvae to pupae to adult -- are going to speed up," he said.

There have been no confirmed cases of a human contracting West Nile virus in Tippecanoe County, Beck said. Still, it has been found in dead birds here since 2001, Beck said. And he said he sees no reason why this year will be any different.

The disease, which causes inflammation of the brain and spinal cord, particularly threatens the elderly and children.

Members of the department are trying to inform the public of the importance of removing water from old tires, buckets, drums, gutters or other items in their yards. After a heavy rain, health department members will also visit places where water is known to pool and take various steps to kill the insects.

Sometimes they use a growth-inhibitor or a bacteria spore to destroy the larvae. If a group of mosquitoes seems near to hatching, the health department will spread a chemical, similar to a mineral oil, over the top of a body of water.

"It just changes the surface tension and suffocates them," he said. "That's the most fast-acting."

All of those methods were chosen specifically for mosquitoes and leave other creatures unharmed, he said. He estimated the health department visits from 75 to 100 different places throughout the county and returns again and again to make sure the efforts have succeeded.

Mosquitoes concentrate particularly on sites where the elderly live or where people are likely to be out at night, said John MacDonald, who is retired from the entomology department at Purdue and now volunteers for the department.

"If the department gets complaints, they'll send someone out to investigate," he said. "We'll talk to them about habitats and what they can do to help themselves."