MOSQUITOE REPELLANTS

                   MOSQUITOE REPELLANTS

                                                              Maneka Sanjay Gandhi

In a previous article I told you about some plants that keep away mosquitoes. Here are some more. None of these are difficult to get : try your local nursery.

Pennyroyal

The European Pennyroyal (Mentha pulegium) is a member of the mint family. It is a low, spreading perennial herb, native to Europe and western Asia. Reaching a height of 0.3 meters, the plant has ovate to nearly round leaves with hairy undersides and lilac flowers in dense whorls. Crushed Pennyroyal leaves have a very strong fragrance similar to spearmint. It is used as a mosquito repellent in the environment and a flea repellent on the body. It is cultivated in parts of India for its essential oil.

Rosemary

Rosemary (Rosmarinus officinalis) is a perennial mint family shrub that can reach 1.5 meters in height. It is a drought tolerant plant with pleasantly fragrant needle-like leaves and white, pink, purple, or blue flowers. Like many of the plants used as repellents, it can also be used in food and medicine.

Lemon balm

Lemon Balm (Melissa officinalis) is also a member of the Mint family. A perennial, it grows to 0.6 meter high. Its leaves are joint toothed pairs, broadly ovate or heart-shaped, which emit a fragrant lemon odour when bruised and can also be used in salads. They are rubbed on the skin as a repellent, though the essential oil would be more effective here. It repels flies and ants as well. It has small white flowers full of nectar . Lemon balm grows in clumps The stems of the plant die off at the start of the winter, but shoot up again in spring.

Pudina

Peppermint (Mentha piperita), pudina, is a perennial plant growing to 0.3–1 meter tall, with smooth stems. The leaves are from 1.6–3.5 cm long, dark green with reddish veins, and coarsely toothed margins. The leaves and stems are usually slightly hairy. The flowers are purple; they are produced in whorls around the stem, forming thick, blunt spikes.

Morpankhi

Morpankhi (Thuja orientalis) is a bush common all over India. It is also known as mayurpankhi • Manipuri: Lairikheibi * Sanskrit: kshirakakol * Bengali: bilatijhau.
Belonging to the cypress family, it is a densely branched evergreen conifer that can become 16 meters tall but is usually grown as a smaller, bushier shrub. The overall shape is conical. The bark is rusty-brown and fibrous. The numerous slender ascending branches are spread out in flat, vertical planes. The leaves are like little scales overlapping and tightly packed. The odd shaped cones are 15-25 mm long, green ripening brown in about 8 months, and have 6-12 thick scales arranged in opposite pairs. Its oils are mosquito repellents. Many villagers squash and rub the seeds on their skin to keep away mosquitoes.

Tansy

Tansy (Tanacetum vulgare) is a perennial, herbaceous flowering plant of the aster family, native to Asia. It is also known as Common Tansy, Bitter Buttons, Cow Bitter, Mugwort, or Golden Buttons. It has finely divided compound fernlike leaves and yellow, flat topped button-like yellow flowers. It has a stout, somewhat reddish, erect stem, usually smooth, 50–150 cm tall, and branching near the top. Bunches of tansy were traditionally placed at windows to keep out flies.

Vetiver

Vetiver (Chrysopogon zizanioides) is a perennial grass native to India. In western and northern India, it is popularly known as khus. Vetiver can grow up to 1.5 metres high and form clumps. The stems are tall and the leaves are long, thin, and rather rigid; the flowers are brownish-purple. Unlike most grasses, which form horizontally spreading, mat-like root systems, vetiver's roots grow downward, 2–4 meters in depth. Vetiver grass grows in bunches. The vetiver plant is highly drought-tolerant and, if made into a hedge barrier, can keep away mosquitoes and other pests.

Sagebrush, Wormwood, Mugwort are all members of the Artemisia family of plants. All of these species can be used as an aromatic smudge that is known to be a very effective mosquito repellent. The crushed leaves can also be applied directly to the skin. These species grow in drier habitats. 

Mosquitoes are repelled by a type of lemony scent. The most effective is citronella grass. In Africa they use the Citronella mucrunata a tree /hedge which has proven most effective in repelling mosquitoes. 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 compound has also been bred into the 'lemon geranium' which exudes the same scent, and is being used to repel mosquitoes. Lemon geraniums, which I wrote about last time, 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.

Mosquito repellents should be adopted by housing societies. Vetiver and Citronella are grasses that can be planted round the periphery of the complex. The clove tree Syzygium aromaticum could be planted, but until it grows, use clove oil as an insect repellent by diluting it with distilled water, and using 1 part clove oil to 10 parts of the diluting solution, pour into a plastic spray bottle. Apply the solution to outdoor areas such as broad-leafed plants, planters and fences, forming a perimeter around your outdoor activity area. You may need to reapply the solution every 1 to 2 hours for maximum protection, so use it before a party or a sit out.

Citrus trees of any kind – lemon, lime, pomelo, grapefruit, for instance - grow easily and are definite mosquito repellents. So are tomatoes that could grow on pots on windowsills. Eucalyptus trees are definitely mosquito repellents but I hesitate to recommend them because they drink so much water.

                                           Prof. John Kurakar