Natural Fly and Insect Repellents - Safe for you, deadly for insects!

Concerned about the toxic chemicals in your insect repellents? DEET is a common ingredient found in many products available. This pesticide, although very effective in deterring mosquitos and biting flies, can have side effects such as memory loss, fatigue, headache, weakness and muscle and joint pain. It is also not recommended for use on infants and young children because of its toxicity. There are safe alternatives to using such chemicals. Many essential oils have been proven to have effective deterrent properties and can be used in many different ways in animals, adults and children.

Let’s talk bugs

It’s only the female mosquito that bites. She needs the protein derived from blood to feed her babies. Most of these bites are a nuisance, leading to localised redness and itchiness. However, some mosquitos can transmit infections. In Australia, the most common mosquito borne diseases include:

• Dengue fever
• Australian encephalitis
• Ross River virus disease
• Barmah Forest virus

Although probably more annoying than dangerous, the common house fly is capable of spreading food-borne illnesses.

Biting flies, such as the march fly, black fly or sand fly, are usually of higher concern as their bites are painful and leave a very itchy, inflamed area of the skin. It is also common for people to have allergic reactions to fly and mosquito bites.

What attracts them?

Mosquitos and the bush fly are attracted to heat and carbon dioxide. When close enough, they are either repelled or attracted to the hundreds of chemicals our body emits. These chemicals can be obtained from our diet, our genes and bacteria on the skin.

Ever wondered why some people are bitten by mosquitos more than others? Here’s some interesting facts:

• One particular species of mosquito loves blood group O
• The mosquito Aedes Aegypti are attracted to lactic acid which is a by-product of sweating
• Mosquitoes love people who drink beer
• They prefer pregnant women to non-pregnant women
• Darker clothing can attract them more
• They usually prefer males because of their greater mass which equals greater heat and carbon dioxide
• Hair on arms and legs can act as a physical barrier preventing getting bitten

Essential oils: use and safety

Essential oils can be used in a variety of ways but are most successful when applied directly to the skin in a diluted form. Sweet almond, olive, sunflower or coconut oil can be safely used as a carrier oil. For adults and children over the age of 12 add approximately 5 drops of essential oils to 1 tablespoon of oil. It’s important to patch test a small spot on the skin to check for any adverse reactions before applying to larger areas. Alternatively, oils can be diluted in vinegar or water and sprayed into a room, onto the skin and clothing. Wristbands with essential oils are also readily available and suitable for very sensitive skin.

Safer oils for use with babies and children under the age of 2 include dill, yarrow and lavender. When using on the skin don’t apply onto the face or hands. Apply a small amount to the feet (that is if they don’t stick them in their mouth) and the forearms and legs only if very necessary. When applying topically use one drop per tablespoon of oil. Be very careful for use in children with asthma.

Essential oils set to rival DEET

Citronella oil

Citronella oil is probably the most well-known natural, non-toxic mosquito repellent that can also repel black flies. It can be applied on the skin and clothing in the form of a patch, wristband, liquid or oil. Citronella candles and cartridges can also be used outdoors as a deterrent.

Citronella collars are safe to use on pets and can also be an effective measure against fleas, biting flies and ticks. The active compounds responsible for repelling mosquitos include camphor, eucalyptol, eugenol, linalool, citronellal and citral. Studies suggest that these compounds interfere with mosquito olfactory receptors and are responsible for their repulsion.

Neem oil

Neem oil provides protection against bites from a wide range of mosquitos by affecting their behaviour and physiology. In one study, Neem oil was mixed with coconut oil and applied to the skin of human volunteers. It demonstrated 12 hour protection from mosquito bites. Another study found it very effective in preventing sand fly bites. Neem oil is relatively inexpensive and non-toxic to both animals and humans. It can be particularly useful for prevention of malaria in endemic countries.

Lavender oil

Lavender oil has been proven, in many studies, to have control potential against mosquitos and the most common species of the fly, the house fly. In one particular study, when mixed with geranium oil and diluted to 30% it was capable of 100% repellences. It was also included as part of a study of the insecticidal activity of six Mediterranean plants yarrow, lavender, curry plant, fennel, myrtle and rosemary. All herbs were shown to decrease the concentrations of mosquito larvae.

Peppermint oil

Peppermint oil has remarkable mosquito repellent activity against Aedes aegypti adults and is capable of killing larvae from a range of species, especially the species that transmits Dengue fever. When the oil is applied topically on the skin it is capable of strong repellent activity, ranging from 84.5% to 100% depending on the species.

Peppermint oil, when mixed with geranium, lemongrass, lavender and basil essential oils, can repel flies for up to 8 hours.

This is a very short list as there are many more essential oils which possess remarkable repellent activity. Other oils worth mentioning include eucalyptus, cedar, tea tree, cinnamon and clove.

General advice

• Wear light coloured clothing and long tops, socks and anything else that can act as a physical barrier.
• Avoid staying outdoors between dusk and dawn which are the peak mosquito biting times.
• Eliminate any standing water by removing empty pots, animal water bowels, bird baths and anything else that can accumulate water to reduce the amount of mosquitos in your immediate vicinity.
• Don’t leave food out and put lids on bins as flies are attracted to decaying food.

Synthetic chemicals in many insect repellents can be toxic, especially to the nervous system and are not recommended for use in young children. Naturally occurring botanical compounds possess a range of active constituents which naturally deter mosquitos and biting flies and are safe to use for animals, children and adults.

References

1. Swale DR, et al. Neurotoxicity and mode of action of N, N-diethyl-meta-toluamide (DEET). PLoS One. 2014 Aug 7;9(8):e103713 https://www.ncbi.nlm.nih.gov/pubmed/25101788
2. http://www.medent.usyd.edu.au
3. http://www.news.com.au/lifestyle/why-do-flies-bug-us-so-much-the-csiro-helps-dispel-urban-myths/story-fneszs56-1226742489310
4. http://www.abc.net.au/radionational/programs/greatmomentsinscience/why-do-mozzies-love-some-people-but-not-others/7868658can
5. Shao Q, et al. Zika virus infection disrupts neurovascular development and results in postnatal microcephaly with brain damage. Development. 2016 Oct 11 https://www.ncbi.nlm.nih.gov/pubmed/27729407
6. Geetha RV, Roy A. Essential oil repellents- A short review. Int J of Drug Develop. June 2014.
7. http://www.ijddr.in/drug-development/essential-oil-repellents-a-short-review.php?aid=5498
8. Lachance, Grange G. Repellent effectiveness of seven plant essential oils, sunflower oil and natural insecticides against horn flies on pastured dairy cows and heifers. Med Vet Entomol. 2014 Jun;28(2):193-200 https://www.ncbi.nlm.nih.gov/pubmed/24382265