Monday, October 13, 2008

Mosquitos and You (West Nile)

“Mosquitoes and You” or “Buzz Off”!!

Steady winds and dry summers all combine to allow many of us in Metchosin to brag about the few mosquitoes we encounter in our yards. With the imminent arrival of West Nile disease we want to ensure that we retain our bragging rights.
There are many simple steps we can take to reduce the chance of mosquitoes breeding in our yard or if they are there, to make sure their predators are there too.
There are 2500- 3000 species of mosquitoes worldwide, of which 46 species reside in BC. They all share a similar life history that takes place in the remarkably short span of seven days. Many species can use any small container of standing water in which to reproduce; from old tires to flower pot saucers, from bird baths to bottle caps. Yes, four mosquito larvae can live in the stagnant water in a bottle cap! Be vigilant, search your property and empty all containers, even those non-biodegradable plastic fast food containers or the cellophane from a discarded cigarette pack.
➢ At least once a week, empty water from flower pots, pet food and water dishes, livestock watering troughs, birdbaths, swimming pool covers, buckets, barrels, and cans.
➢ Check for clogged rain gutters and clean them out.
➢ Remove discarded tires and other items that could collect water.
➢ Be sure to check for containers or trash in places that may be hard to see, such as under bushes or under your home.
Once you have done all you can to ensure you are not inviting mosquitoes to your breed on your property, then you need you need to mosquito proof yourself and your family.
➢ Deet is the active ingredient in chemical mosquito repellent that seems to offer the greatest degree of protection. Apply sparingly to exposed skin. The more DEET a repellent contains the longer time it can protect you from mosquito bites. A higher percentage of DEET in a repellent does not mean that your protection is better—just that it will last longer. DEET concentrations higher than 50% do not increase the length of protection. Choose a repellent that provides protection for the amount of time that you will be outdoors. Do not use on children under 2 months of age.
➢ Keep away from the eyes, nose and mouth, so avoid applying repellent to the hands of children.
➢ Pregnant women should minimize use.
➢ Wash treated skin after coming indoors.
➢ Spray clothing with repellents containing permethrin or DEET since mosquitoes may bite through thin clothing. Products containing permethrin, derived from a species a chrysanthemum, are very effective in killing mosquitoes on clothing and fabrics. Do not apply repellents containing permethrin directly to exposed skin. A combination of permethrin on clothing and a skin safe product on your exposed skin, gives the most effective protection. Spray repellant onto mosquito netting that you hang around your bed or camp-cot. This will give the double benefit of excluding the mosquitoes and poisoning the insects as they rest on the netting.
➢ Place mosquito netting over infant carriers when you are outdoors with young babies.
For those who are uncomfortable with chemical insecticides; there are a number of plants that have been identified as having some mosquito repellent success. The following is gleaned from various sources and has not been verified.
➢ Citronella, cedar, catnip, verbena, lantana, pennyroyal, geranium, lavender, pine, cajeput, cinnamon, rosemary, basil, thyme, allspice, garlic, lemongrsss, eucalyptus and peppermint. These are often mixed in combination with tea tree oil, coconut oil, soy oil or almond oil.
➢ The following is a sample recipe for a do it yourself repellent:
20 drops Eucalyptus oil
20 drops Cedarwood oil
10 drops Tea Tree oil
10 drops Geranium oil
2 oz. carrier oil ( such as Jojoba )
Mix together in a 4 oz. container. Apply to skin as needed avoiding the eye area. Keep out of reach of children. Test on a small area of skin for sensitivities . Experiment with different percentages of essential oil.
➢ Half and half clear, real vanilla (not extract) and water
➢ Some people swear by Vick’s Vapo-Rub
➢ One vitamin B-1 (Thiamine Hydrochloride 100 mg) tablet a day April through October. The odor the tablet gives out through your skin (YOU can not smell it) repels mosquitoes, black flies, no-see'ms, and gnats. It does not work on stinging insects.
Products which apparently don’t work include electronic “bug zappers” and sonic repellers. The bug zappers are reported to be much more likely to attract and kill almost any other flying insect.
Research seems to indicate that mosquitoes are attracted to skin temperature, moisture, carbon dioxide (exhaling), lactic acid (produced in muscles from exertion and found in sour milk) and floral fragrances. Strategies that reduce these attractants can be helpful.
➢ When possible, wear light colored long-sleeved shirts and long pants whenever you are outdoors.
➢ Consider staying indoors at dawn, dusk, and in the early evening, which are peak mosquito biting times.
➢ Install or repair window and door screens so that mosquitoes cannot get indoors.
➢ Avoid perfumes, sweet oils, creams and eating bananas as these seem to attract mosquitoes
This seems to suggest that lying around wearing light coloured clothing, breathing shallowly and perhaps sipping a non-sweet beverage might be the best method to get through mosquito season!
To mosquitoes, we are not all created equal. They show a preference for adults over children, although this drops off as we age and for men over women, which is a sexist bias I can live with! Larger people can also be unfairly singled out, perhaps because of greater relative heat and/or carbon dioxide output.
Before you decide to blacktop your local pond or lake, the Indiana Department of Natural Resources claims a healthy wetland provides habitat for many unique animals -- including the natural enemies of mosquitoes. Mosquito populations are held in check in by birds, bats, frogs, fish and insects that feed on mosquito adults and larvae. Wetlands can decrease mosquito populations by providing proper habitat for such predators. For example, when Essex County, Mass., restored a 1,500 acre wetland, the mosquito population dropped by 90 percent. Other states, such as New Jersey, have also been controlling mosquitoes the "natural way" by eliminating small, stagnant breeding depressions and using water management practices to increase mosquito predators. These "natural methods" reduced the cost of mosquito control over the traditional method of insecticide application, by more than 97 percent. Some of these aquatic predators include dragonflies, damselflies, water striders, backswimmers, predaceous diving beetles, topminnows and mosquitofish. Even our native sticklebacks will feed on mosquito larvae.
Mosquitoes are an important part of the food chain and we can get help from our wild neighbours to keep them in check. Erect birdhouses that will attract insectivorous birds such as purple martins and swallows. Some swallows have been found with approximately 1000 mosquitoes in their stomachs! The addition of bat boxes is also a good idea. For example, a single little brown bat can consume 1,200 mosquito-sized insects in just one hour.
If you find dead birds, especially crows and jays, that you suspect of having West Nile, do NOT contact the BC Centre for Disease Control (BCCDC) or our local Public Health branch. They are able to collect sufficient birds for testing. Dispose of the dead birds as you would normally. Wear gloves, bury or double bag and dispose of in the garbage and wash your hands.
Most of the agencies handling information on West Nile disease stress that it is unlikely that any one person will contact the disease and even more unlikely that it would develop into a serious illness.

Much of this article was plagiarized from the following sites:

Further information on West Nile disease and reducing the risk of mosquito bites can be found through the BCCDC at their website:
Information on bats and bat house plans can be found at:
Be prepared, this next site comes with the very annoying sound of a whining mosquito
The Canadian Centre for Disease Control:
A child friendly site showing the life history of mosquitoes:

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