From Green Right Now Reports
With the U.S. in the grip of possibly the worst outbreak of West Nile Virus ever, people need to do all they can to avoid getting bitten by the Culex mosquito that carries the disease and reduce the mosquito population in their yards.
The Texas State Department of Health counsels residents follow the Four D’s:
- Drain all standing water in containers or gutters.
- Dress in light-colored, long-sleeved clothing when outdoors.
- Deet, use repellents that contain Deet. Picaridin, IR3535 and the plant-based oil of lemon eucalyptus also are approved by the CDC as being safe and effective. Check for how long these repellents last at this EPA page. Deet in higher concentrations can be used on top of clothing; people with sensitive skin or concerns about DEET may prefer to use the plant-based products for skin contact.
- Dusk or Dawn. Remain indoors during these periods when mosquitoes are most active, or if you must be out, wear a DEET-based repellent.
Beyond that, residents may be able to repel or reduce the mosquitoes living and reproducing in their yards by applying botanical oils that mosquitoes find disagreeable. A caveat: These products are no substitute for protecting your person (please refer back to the advice above). But they could reduce the mosquitoes breeding in and visiting your yard.
- Dr. T’s Nature Products Mosquito RepellentA natural formula of spreadable granules that includes lemon grass, mint and garlic oil.
This 5 pound container of repellant can be applied with the built-in sprinkler cap or using your fertilizer spreader. It contains enough granules to protect up to 4,000 sq. ft, according to the company, and will become effective within an hour. For ideal efficiency, the formula should be applied every 2 to 3 weeks. It is safe for your lawn, patio or pool because it’s biodegradable. $13.95 a gallon at Home Depot and available at many other locations. (Note: We weren’t able to include the percentage of oils in this product, because it wasn’t available on the MSDS sheetfiled with the EPA.)
- Terro Mosquito RepellentAnother granule product that is made with a blend of botanical oils, such as castor oil (8.5%), garlic oil (0.9%), citronella oil (1.6%).
The carrier ingredients are corn fiber and clay. This is another product that’s virtually harmless to humans and other life, but serves as a deterrent to mosquitoes. $12.97 for a 32 ounce box at Home Depot.
- Sentry Mosquito Repellent This one uses geriniol and cedar oil, in small concentrations, but some customer reviewers were pleased. These plant-based repellents are as natural and safe as the garlic and lemongrass oils of the other products (don’t get this in your eyes). $39.97 for two gallons at Home Depot. (Given that this product has less than one percent of these oils, each, we’re wondering about making our own with essential oils from the natural food market.)
Don’t forget your Mosquito Dunks, for use in any standing water. These kill the mosquito larvae with a bacteria that won’t hurt other organisms.
The Centers for Disease Control has recorded 1,118 cases of West Nile Virus as of Aug. 22, 2012, including 14 deaths.
About half of those human illness cases have been in the North Texas region, the hardest hit area.
Dozens of people who’ve survived the illness are likely to experience neurological issues, paralysis or cognitive deficits for months or permanently, officials said.
West Nile, transmitted by the Culex or house mosquito, would normally start declining by late August, but because the disease takes a few days or even a week to cause symptoms, the CDC authorities said they expect human cases to continue for the immediate future.
The incidence also is moving northward as the summer progresses, leading to more cases in the Midwest.
The extreme heat of the summer, as well as the unusually warm winter and early spring likely played a role in the outbreak, said Dr. Lyle Petersen, director of the Division of Vector-Borne Infectious Diseases at the the CDC.
Hot weather “seems to promote West Nile virus outbreaks,” Petersen said in a press briefing. “And most — many major West Nile virus outbreaks in Europe, in Africa and now in the United States, have occurred during periods of abnormally hot weather. Hot weather, we know, from experiments done in the laboratory, can increase the transmissibility of the virus through mosquitoes and that could be one contributing factor.”
Studies show that warm winters are conducive to larger pest populations, including mosquitoes. The Culex mosquito also thrives when shallow, short-lived pools of water form, creating ideal breeding grounds for their larvae. Scientists have reported that the mosquitoes prefer these temporary ponds to long-lived ponds where natural predators of the mosquito are more likely to feed on the larvae.
That research has given rise to speculation that one way to keep mosquito populations in check would be to encourage a well-rounded biological setting, or diverse setting, that included ample predator insects, otherwise known as “beneficials” with regard to humans.
The Helmhotz Centre for Environmental Research in Europe has put this theory to the test, and found that spraying for epidemic outbreaks with a pyrethrin-based pesticide in combination with ongoing biological methods that target larvae provided the most effective methods of control. These two approaches appeared to reduce the Culex mosquito population and keep it down.