To help prevent mosquito bites, eliminate their preferred environment

The Southern Nevada Health District released a press release this month that stated the first West Nile virus-positive mosquitoes of the season were identified in the 89005 ZIP code through its mosquito surveillance program. West Nile virus is the leading cause of mosquito-borne disease in the continental United States. It is most commonly spread to people by the bite of an infected mosquito.

The most effective way to prevent infection from West Nile virus, and other mosquito-borne diseases, is to prevent mosquito bites. Mosquitoes bite during the day and night. Use insect repellent, wear long-sleeved shirts and pants, treat clothing and gear, and take steps to control mosquitoes indoors and outdoors.

Use Environmental Protection Agency-registered insect repellents with one of these active ingredients: DEET, picaridin (known as KBR 3023 and icaridin outside the U.S.), IR3535, oil of lemon eucalyptus, para-menthane-diol or 2-Undecanone.

When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women. Always follow the product label instructions. Reapply insect repellent as directed. Do not spray repellent on the skin under clothing. If you are also using sunscreen, apply sunscreen first and insect repellent second.

Use permethrin to treat clothing and gear (such as boots, pants, socks and tents) or buy permethrin-treated clothing and gear. Permethrin is an insecticide that kills or repels mosquitoes.

Prevent mosquito bites when traveling overseas. Choose a hotel or lodging with air conditioning or screens on windows and doors. Sleep under a mosquito bed net if you are outside or in a room that does not have screens.

It’s also important to stop mosquitoes from laying eggs in or near water. If you have a concrete or above-ground swimming pool know that chlorine will not always kill mosquito larvae. If a pool cover is used, keep it tightly sealed, and remember to remove rain water from the top of the pool cover.

Water in plastic wading pools should be changed every week. The pools should be stored indoors and upside down when not in use.

Stock unused or “out-of-order” pools with mosquito fish. Most fish eat mosquito larvae and are useful in keeping ornamental ponds free of mosquitoes. Gambusia affinis, called “mosquito fish,” eat mosquito larvae as fast as they hatch from the eggs laid by the mosquito. They require no special feeding, and care is limited to protecting them from garden sprays and from chlorine or chemicals used to clean the pond.

Mosquito fish do not lay eggs, but give birth to well-developed and active young. They breed throughout the summer and a new brood is produced at intervals of about four to six weeks. Approximately 100 young are in a single brood, each about a half-inch in length when born. They are ready to begin the work of destroying mosquito larvae at once. Gambusia grows rapidly, reaching a maximum size of about 2 inches. The earliest broods of the season, born in April and May, become sexually mature and produce young when 4 to 5 months old. Contact the Southern Nevada Health District office at 702-759-1633 to pick some fish up for free.

Fish also can be stocked in ornamental ponds. Be sure to avoid using garden insect spray on them, remove leaves and thin out plants, keep the water level up and screen the inlet of the recirculation pump.

When cleaning the pond, transfer the fish to a glass bowl so they won’t be killed by the chlorine.

If the pond is no longer desired, break holes in the bottom and fill it with dirt or sand.

You should also prevent accumulation of sprinkler or rainwater in boats. Store small boats upside down or cover them to keep out the rain and water from your sprinklers.

Large animal water troughs can be stocked with mosquito fish. Small troughs should be cleaned every week.

To prevent standing water from accumulating, containers such as cans, jars, barrels, old tires, buckets and tubs should be removed and disposed of.

Home gardeners who are rooting plant cuttings in vases, buckets, etc., should change the water every week. Containers that are not being used at the moment should be stacked upside down.

Also be aware of other sources of standing water that can accumulate under the house. Be sure to repair leaking plumbing, prevent seepage from garden irrigation, divert storm water away from foundations, watch the drain outlet from the air conditioner and keep rain gutters clean and free of debris so water drains properly.

Contact your local code enforcement office if you see any standing or green water in the community, or to report a green swimming pool. Boulder City has online forms that allows residents to submit concerns 24/7 at http://www.bcnv.org/634/Complaints. If it is easier to call or if you have questions, the city has two phone numbers where you can leave a message anytime: 702-293-9266 for city property concerns and 702-293-9597 for private property maintenance concerns.

To Your Health is provided by the staff of Boulder City Hospital. For more information, call 702-293-4111, ext. 576, or visit bouldercityhospital.org.