07/03/2015

Natural Mosquito Repellents

Maneka Sanjay Gandhi

(Bihar Times)What are the awful choices that victims of mosquitoes have to face? Either being tortured by being bitten millions of times, or never venturing out in the evenings, covering yourself from head to toe and still being bitten right through a T-shirt or socks, getting malaria or dengue. Two children a day die in India from being bitten. And as global warming increases, mosquitoes will increase their spread and ferocity.

The other choice is to use the chemical repellents on the market – all of which have poison clearly marked on them, and die of something else. The repellent sprays mostly use diethyl-meta-toluamide (DEET), a chemical that can cause rashes, swelling, eye irritation, brain swelling in children, anaphylactic shock, low blood pressure and even death. You can rub that dreadful chemical cream all over you and stink. Then you can use insecticide incense coils and keep the mosquitoes away. The point is that they stink just as much and are also poisonous.

So what can be done?

Why not grow and make your own repellent. Plant a few stalks of lemon grass (Cymbopogon citratus) anywhere in your garden or in pots in your verandah. Within a few months they will become clumps. You can use the stalks as herbs in your salad. It grows quickly. It keeps the mosquitoes away. It contains something similar to citronella oil but is far more effective.

You can rub the long, grassy leaves on the skin, but the stalk works even better.

Here is how one user describes it - “Take one stalk of fresh lemon grass. Grip it near the ground and give it a sharp sideways tug to break it off from the clump. Peel off the outer leaves, snap off the grass blades behind the swollen stem at the base. Bend the stem between your fingers, loosening it, rub it vigorously between your palms so that it fractures into a kind of fibrous juicy mass, and rub this mass over all exposed skin, covering thoroughly.”

It has a pleasant smell and the protection lasts a minimum of 4-5 hours.

You can make a tincture of lemon grass that can be sprayed. Some people use a base of gin or vodka. Chop up the cores of five or six stalks of lemon grass, put them in a blender with a tumblerful of spirits, blend thoroughly, strain, and put it in a sprayer.

Actually you don’t need alcohol to dissolve the lemon grass essential oil. It works just as well if you blend it with water and shake the sprayer before using it.

If you can’t grow lemon grass just buy some lemon grass essential oil, which is easy to find and not expensive. Add a couple of other essential oils for extra effectiveness: a combination of lemon grass oil, citronella oil and eucalyptus oil gives good protection all day. Mix about 1 ml each of lemon grass oil, citronella oil and eucalyptus oil with 100–150 ml of water.

Other plant oils mosquitoes don't like are citronella, jojoba, neem, witch hazel, tea tree oil, peppermint, lemon basil, lemon oregano, lemon geranium, catnip, eucalyptus and pennyroyal.
Deforestation and unchecked growth of cities without planned sewage are two of the factors causing an alarming increase in mosquitoes. The World Health Organization says “global warming is also expanding the range of mosquitoes that carry malaria, putting millions more humans at risk. Malaria mosquitoes (Anopheles sp.) are appearing in areas where they've never been seen before. In the history of the world, more people have died from diseases transmitted by mosquitoes than from all the fighting in all the wars.” Malaria infects approximately 110 million people a year, and with increasing drug resistance, the problem is worsening, while attempts to control the mosquitoes with pesticides have proved ineffective. In fact countries like India, who still have not banned DDT, kill an even larger number of humans and just through malaria. There are 50 million cases each year of dengue and the incidence is rising.

Bed Nets were proposed as the answer and thousands of chemically treated mosquito nets were given away free in Africa. But, according to a study from Senegal published in The Lancet, mosquitoes quickly develop resistance to bed nets treated with insecticide.

So, the search needs to intensify for safe, cheap, effective, locally available alternatives to insecticides and to the malaria drug treatments that no longer work. In other words, plants.

Chinese scientists have extracted an anti-malarial drug from the Artemisia annua fern, traditionally used against malaria for hundreds of years. It is now used in many countries and is proving effective.
In India, a homemade mosquito repellent against the Anopheles mosquito can be made from low-cost neem oil from the neem tree Azadirachta indica mixed with coconut oil in concentrations of 1-2. Neem is also proving effective against malaria itself, not just the mosquito that carries the parasite. One active component of the plant, gedunin, is said to be as effective as quinine on malaria-infected cell cultures.
Peppermint oil is also turning out to be a new, cheap weapon in the fight against mosquito-borne diseases such as malaria, filariasis, dengue fever and West Nile virus. The oil not only repels adult mosquitoes but also kills the larvae. It is particularly effective against the Anopheles culicifacies mosquito.
Another promising candidate is catnip. Researchers report that nepetalactone, the essential oil in catnip, is about ten times more effective at repelling mosquitoes than DEET – the compound used in most commercial insect repellents.

The women of my Parliamentary constituency Pilibhit have an answer that I have been using for years. It is a combination of large round cow dung tablets mixed with samagri. Light one up and take it round the house. The mosquitoes keep away and the air smells as if you are doing a pooja havan in the house. It should be on sale in a few months as an entrepreneur is working with them. The machine was designed by Prof. Anil Gupta of IIM Ahmedabad’s group and I hope this solves the poverty problems of some women, the gobar problems of the gaushalas and the mosquito problems of India.