Northwood News ♦ April 2003

Fighting West Nile Virus By Battling Mosquitoes

By Marilyn Piety

Our biggest mosquito problem is Asian Tiger mosquitoes. The best way to keep them out of your yard is to get rid of places mosquitoes can breed. Asian Tigers breed only in small containers like flower pots, kids toys, downspout extensions, and other places on the attached checklist. They must remain in water for at least a week because it takes that long for the eggs to complete their life cycle to become adult mosquitoes. If you dump the water out, the eggs can never become adult mosquitoes. What could be easier? But everyone in the neighborhood must get rid of their standing water once a week. (See the checklist below to correct breeding sites.)

Asian Tigers do not fly very far. Their maximum flight range is about 200 yards (600 feet, not backyards). This means, if you have Asian Tigers in your yard, they are breeding in your yard or, perhaps, that of a nearby neighbor.

Public Health Services, in conjunction with the County’s Volunteer Center, teaches residents how and where to find places where mosquitoes are breeding. It is good for neighborhoods to have residents trained to help each other. One training is scheduled for Thursday, 17 April, at 7:30 p.m. at the Takoma Park City Hall. Everyone is invited. No reservation is required.

If people are interested in other training, they can call the Volunteer Center, 240.777.2600, to learn where other training sessions are currently scheduled. Or they can leave their phone number to be notified as other training is scheduled. It is early in the season now. More will be scheduled.

2002 was the largest recorded arboviral outbreak in the Western Hemisphere. (Arboviral means virus carried by arthropods such as mosquitoes, ticks, etc.) 2003 will probably be bigger.

Please feel free to call me (240.777.1394) if you need more information.

[Marilyn Piety is Program Manager for Montgomery County Public Health Services.] ■

Use This List to Check for Mosquitoes’ Artificial Breeding Sites

Potential Breeding Site	How to Correct
Any container capable of holding water	Throw away, turn over, empty once a week, or drill holes in the bottom.
Bird baths	Dump out once a week or flush out with garden hose.
Pet water bowls	Rinse out once a week.
Potted plants with saucers	Empty saucers or flush out with garden hose once a week.
Buckets, watering cans, drinking glasses, styrofoam cups, bottle caps, foil, other trash that can hold water	Store inside or turn over. If trash, throw away.
Tarps or other plastic covers, flexible sandbox covers	Drain water trapped in folds and arrange so that water runs off.
Gutters, including “covered” types	Clean so water runs freely.
Garbage cans, other barrels Upturned garbage can lids	Keep can covered or drill holes in bottom. Keep lid on can or turned so water runs off. If collecting rain water, cover with screen.
Old tires	Dispose of at Solid Waste Transfer Station, Shady Grove. If used for playground equipment, drill holes for water to run. If on ground, be sure holes are not blocked by mulch.
Old playground equipment	Remove and dispose of. If it must be stored, put under cover. Be sure water drains off.
Children’s toys, especially plastic toys, “Kiddie Coops,” etc.	Store inside or turn so that places that can hold water are turned down. Some toys have compartments that hold water on both sides.
Wading pools, unused or abandoned swimming pools	Turn over kiddie pools when not in use. Larvicide unused swimming pools with “mosquito dunks” once a month. (Mosquitoes can’t breed in maintained pools because of the chemicals used.)
Wheelbarrow stored outside	Turn over when not in use.
Flat roofs	Inspect for water pools.
Dripping outdoor faucets and window air conditioners	If puddling, repair faucet. Place rocks under window air conditioner to ensure water runs off or fill hole with dirt.
Ornamental ponds without fish	Stock with fish, apply larvicide or filter/aerate water. (Fish eat mosquito larvae.)
Boats, canoes	Pump out bilges. Turn over canoes and small boats. If not possible, dump out after each rain.
Under decks, porches, or outbuildings: stored items, depressions in dirt, or plastic ground linings	Fill in depressions. Remove or turn over any stored items that hold water.
Pipes, plumbing supplies with corner joints	Store under cover. If they must be outside, arrange so openings point down, not up.
Drainage ditch, culvert or other low areas clogged by grass and weed clippings	Remove grass and weed clippings so water can flow and/or drain freely.
Flexible plastic pipe to take water away from downspout	Replace with smooth pipe. The grooves can hold enough water to breed mosquitoes. Or fasten screen or old nylon stocking to end.
Base of patio umbrella or portable basketball stand	Fill with sand or, if filled with water, be sure to screw on plug. Keep water out of depressions on stand also.
Outdoor grills	Keep covered. Be sure vent is closed also.
Bromeliads (plants that hold water), holes in trees or cavities formed by multiple trunks	Turn plant over to dump water. For trees or plants too large to turn over, flush out cavities with garden hose once a week.
Outside drains	Cover with screening or larvicide with “mosquito dunks/pellets.”
Sump pumps	Cover with screening
Bamboo	Cut down and regularly mow remaining “stumps” so they can’t hold water
Hollow fence posts without caps	Put caps on open chain link or plastic fence posts.
Plastic in gardens to prevent weeds	Use landscape cloth that will allow water through instead of plastic sheets.