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Vector Control focuses on mosquito larvae

A few years ago, controlling mosquitoes was simple. Call vector control, set a date, and Jim would come by and spray. No vector control now. We are supposed to locate where the mosquitoes are, etc. This is ridiculous. My yard is already buzzing. Unless things have changed since I called last year, homeowners seem to be on their own! What gives?

— Judy, Talent

Instead of focusing on adult mosquitoes, Jackson County Vector Control is now trying to get to the root of the problem and go after mosquito larvae, said Jim Lunders, manager for the local agency that tackles pest problems.

"We need to find those larval sources and treat the mosquitoes as larvae before they become biting, flying mosquitoes," he said.

Vector Control still will spray areas for adult mosquitoes on occasion, but the priority has shifted to eliminating the problem at its source rather than spraying one hatch after another.

Mosquito larvae swim around in sources of water that can include low areas where water pools, storm drains, pools that aren't being maintained, flood-irrigated pastures, artificial wetlands built to control storm water, old tires and a host of other places, Lunders said.

"If we map the larval source, hopefully we won't have to treat for adult mosquitoes next time. If we just simply went out and sprayed and the source was still there and full of larvae and pupae, it would just require another spray," he said.

Once they've identified larval sources, vector control workers can put naturally occurring soil bacteria in the water to control the larvae, he said.

Last year, Jackson County Vector Control mapped several thousand new sources for larvae, Lunders said.

Changing federal rules also are pushing the change. Under new national environmental guidelines, vector control agencies must follow integrated pest-management standards, which include first identifying the pest problem, evaluating appropriate options, then determining the best use of pesticides. Spraying adult mosquitoes is now considered a secondary control method.

Jackson County Vector Control recommends members of the public take these steps to help eliminate mosquitoes on their property:

  • After each rain, take a few minutes and inspect your yard, and dump out water from any household containers, such as buckets, flowerpots and old tires that may breed mosquitoes.
  • Don’t forget to check for clogged rain gutters, tarps over wood piles and boats that may also be holding water.
  • If you are collecting rainwater for later use, be sure that barrels or cisterns are covered with fine mesh screen to keep mosquitoes from using them as a home.
  • Ornamental ponds and stock troughs should be stocked with mosquito fish to keep mosquitoes at bay.
  • Dog dishes and bird baths should be cleaned weekly. Anything that holds water for seven days can produce mosquitoes.

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