West Nile Virus a continuing concern in mosquito areas
April 30, 2009 · Updated 2:49 PM
The dog days of summer in Bonney Lake can bring hot weather and mosquitoes.
Those biting bugs are more than a nuisance. Mosquitoes can carry the West Nile Virus, which can be harmful (and at times deadly) to humans and animals.
Agricultural producers and homeowners need to control mosquitoes in light of the virus, first found in the Pacific Northwest in the summer of 2002.
Bonney Lake is surrounded by bodies of water, but streams, lakes and natural bodies of water are not the culprit when it comes to breeding areas for mosquitoes.
"Flowing streams and running water is not the problem with mosquitoes," said Janet Sears, spokeswoman for Washington State University Pierce County Master Gardener program. "Old tires, boats, tarps, things not being used that collect water is where mosquitoes will breed."
The mosquito goes through four growth stages in its life cycle, and three require standing water. The adult mosquito requires a water source to lay its eggs. The mass of eggs, often called a raft, may be found at the surface of body of water. Within as few as seven days, the eggs will hatch and go through all the stages requiring water, becoming a flying adult.
"Therefore, the elimination or management of standing water is the best way to prevent mosquitoes," said Keith Underwood of Washington State University's Pierce County Extension faculty.
This can be as simple as making sure all trays under a potted plant are drained shortly after each plant is watered. Other suggestive preventive actions:
Check and clean pets' outside watering bowls.
Keep all cans, tubs and other items that can trap and store water in a place where they cannot collect water.
Remove plastic and/or tarps and store them inside to prevent water from collecting in them.
Recycle old tires or at least drill holes in the sidewalls and tread areas to allow water to drain.
Store snow tires inside to prevent water from settling inside the tires.
If you have a cistern or rain barrel collection system, keep a tight lid or fine screen over the tops of the containers.
Take a look around the yard to see what else might be there to trap or store water.
Clean rain gutters and downspouts to ensure there are no blockages that can hold water.
Make certain hoses and outside faucets don't drip and create standing water.
Birdbaths or other vessels that hold water throughout the summer, like a pond or water fountain, or child's wading pool, are breeding areas for mosquitoes. These should be drained on a weekly basis to remove the potential for larvae to develop.
"Remember that the mosquito can lay and develop into a flying adult in seven to 10 days if water is left undisturbed," Sears said. "Never pour gasoline or oil onto water to kill larvae. Research is still being done on purchased mosquito eradicators; use them only when absolutely necessary."
For those with a pond or water feature in the yard, several varieties of goldfish can be purchased to eat the larvae. If these water features are of sufficient depth, the fish will live throughout the year and continue to control these pests on an annual basis.
Agricultural sites have many areas that may attract mosquitoes - water storage ponds, stacks of open buckets, tubs and machinery that are being stored for a short time.
Mosquitoes can be eliminated by simply making sure these vessels are placed in an inverted position or protected location to prevent water from gathering. If a pond is located on the property, remove any floating debris to make the surface more exposed.
Drainage ditches and culverts also offer opportune locations for mosquitoes to breed and raise their young. Keep these areas clear of tall standing weeds to assist with drainage and evaporation of standing water. Water storage ponds can be treated with chemicals, depending on their locations and designed uses.
For further information or to inquire about a possible control method for your specific situation, contact the WSU Pierce County Extension office at 253-798-7180.