Nature’s Mosquito Control: Designing Against Mosquitoes, Malaria and the West Nile Virus

This article from our old site was written by Scott Meister

[UPDATE: The recent announcement of a malaria vaccine is a very welcome development. — Douglas Barnes]

One thing that can always dampen a good summer day is an itchy bite from a mosquito. In some places, a bite from a mosquito can transmit diseases and even end your life. Recent outbreaks of mosquitoes in Texas have caused concern about West Nile Virus. However, Malaria is a global concern. Malaria is the leading cause of death and illness in Rwanda (fightingmalaria.org). According to the Roll Back Malaria website, There are at least 300 million acute cases of malaria each year globally, resulting in more than a million deaths. Around 90% of these deaths occur in Africa alone, and mostly in young children.

In fact, the vast Majority of Malaria deaths occur in Africa where it has been estimated to cost more than US　$12 billion every year in lost GDP. It’s interesting to note, that Malaria could be controlled for just a small part of that sum.

There are two basic approaches to fixing natural problems such as this. The first (and most costly) is the Industrial approach and the second (more reasonable) is to use a more holistic and natural approach.

The commercial/industrial approach mentioned above, involves using potentially harmful insecticides that kill indiscriminately and destroy the web of life without regard to long-term consequences to health and the ecosystem.

Fortunately, for the lesser fortunate people on earth, there is a cheaper, simpler, sustainable and eco-friendly approach to managing and controlling both mosquito’s, Malaria and West Nile Virus. It can be practiced anywhere…even in your own back yard, regardless of whether malaria or West Nile Virus is an immediate threat to you or not. These approaches cost very little, and once implemented…continue to produce long-term results requiring very little energy or money to maintain.

In a healthy, ecosystem, pests and diseases don’t generally run amok for long. This is because nature’s design uses biodiversity and various tricks such as plants with a certain scent, aroma or color and predators, natural barriers and limits, etc to keep everything in check. There are no mono-cultures in nature, there are no “lawns.”

By mimicking nature’s bio-diverse design in our own landscape, we can come up with a way to protect ourselves from the pesky mosquito and the viruses they carry. Sustainable solutions to natural problems such as malaria follow the following formula. Natural Repellent/Barrier, Predator (and predator attractant/habitat), Natural Herbal Antidote. Let’s examine each.

Natural Mosquito Repellents/Barriers

[Edit: Please note that the repellent property of the scent in the plants is only made available when the plant is crushed. The plant growing on its own does not repel mosquitos. — Douglas Barnes]

Mosquitoes are often repelled by scent. The scent that has proven most effective in repelling mosquitoes comes from Citronella macronata, which is a tree that can be planted as a hedge. This serves two purposes, first by exuding the scent which repels mosquitoes, and by providing a habitat and food for birds that eat mosquitoes. The Citronella plant attracts birds with berries, while also providing both nesting for them and cover from it’s own predators. Mosquito repellent and predator attractant and habitat are provided all in one tree. Two hits for the price of one..and once planted, they continue growing, and can give free cuttings/seed to be spread to other areas to grow. Did I say free? Yes, and I’d say that’s a rather cheap solution.

The citronella compound has also been bred into the “lemon geranium” which exudes the same scent, and is being used to repel mosquitoes at the herb layer. Lemon geraniums can be planted under or around windows, or can flank the sides of doorways to repel mosquitoes while providing beautiful flowers and a pleasant lemon scent to any shelter where humans spend time and sleep.

Catnip is another common herb that contains an oil that is supposedly 10 times better at repelling mosquitoes than using the expensive, resource-consumptive chemical DEET. Catnip can also be used as a (mildly stimulating) tea for human consumption.

The popular culinary herb, Rosemary, also has an oil that is effective in repelling mosquitoes. Because it’s a tropical plant, and thus not very cold-hardy, it should be planted in pots in cold climates and taken inside for winter. However, if you’re in Africa, it can be planted in window boxes, hung in pots around windows, or planted with lemon geraniums around doorways. It could even be planted and kept indoors near windows that have a lot of light as an interior repellent.

Citronella grass is a tropical grass that grows to be 6-feet tall, and happens to be where companies get the citronella oil that they put in candles and lanterns that can be burned to repel mosquitoes. While not very practical for the dreaded suburban lawn due to it’s height, it could be planted as a decorative grass to flank windows and doors to help repel mosquitoes.

Another grass that has potential in fighting mosquitoes and malaria is the Vetiver grass, which is a clumping grass helpful in fighting erosion and soil stabilization. Vetiver grass roots are aromatic and have been used to weave screens that can be used on windows and ventilation areas for homes. Spraying these screens with a mist of water, helps to cool air flowing through them while simultaneously enhancing the aroma, and thus repellent power of the screens.

Mosquito Predators, Attractant and Habitat

If we wish to get malaria under control, we need to focus on controlling the mosquito population. We can do this efficiently and effectively by attracting and providing habitat for the mosquitoes natural predators. Some of the more famous of these predators are Bats, Birds, Dragonfly and a fish so adept to eating mosquitoes that it’s taken on the suiting name Mosquito Fish (Gambusia affins). By providing the proper habitat for these creatures, we can have them manage the mosquito population for us.

To invite the dragonfly in to help, we can plant Bullrush and Cattail, two plants that attract this mosquito devouring insect that can eat thousands of mosquitoes. Bullrush and Cattail should be planted around ponds, and these ponds can be used to control mosquito larvae by stocking them with the Mosquito Fish and guppies. These fish can eat thousands of mosquito larvae, helping to reduce the adult mosquito population. If stocking ponds with these fish, care should be taken to also stock the ponds with water plants, as Gambusia also require plants to eat, and to provide breeding cover. The population of larvae that survives to become adult, can be eaten by dragonflies and birds nearby.

Last, but certainly NOT the least, when it comes to mosquito population management, is our champion mosquio predator, the bat. A healthy bat population can devour millions of mosquitos in an evening. To insure that they help clear our surrounding areas of malaria carrying pests…we can build and install bat-houses in a nearby area. Perhaps, a bat-house could be placed on a high post between the pond and living abodes. An extra added benefit to building and installing bat-houses…is that bats also provide a valuable fertilizer in the form of guano. This guano can be harvested from below bat-houses and be used in the garden.