Repel Insects the Natural Way!
With the recent awareness around some of the downsides of chemical repellents and anti-insect solutions, many pet parents are looking for alternative natural solutions. Now there is a light at the end of the tunnel, and it ain’t the locomotive!
The repellency of plant materials 1 has been exploited for thousands of years by man , most simply by hanging bruised plants in houses, a practice that is still in wide use throughout the world. This is because most plants contain compounds that they use in preventing attach from phytophagous (plant eating) insects. These chemicals fall into several categories, including repellents, feeding deterrents, toxins, and growth regulators. Most can be grouped into five major chemical categories:
Read More: Scientists Confirm Folk Remedy Repels Mosquitoes, (ScienceDaily).
- nitrogen compounds (primarily alkaloids),
- proteinase inhibitors, and
- growth regulators.
Although the primary functions of these compounds are to defend the plant against phytophagous insects, many are also effective against biting Diptera and Siphonaptera, especially those volatile components released because of herbivory 2 .
Based on current research, it seems that insects “detect” odours when the volatile odour binds to odorant receptor (OR) proteins displayed on ciliated dendrites of specialized odour receptor neurons (ORNs) that are exposed to the external environment. These are often found on the antennae and maxillary palps of the insects. Plants commonly produce volatile “green leaf volatiles” when leaves are damaged to deter herbivores, and several authors have shown strong responses of mosquito odour receptors to this class of volatiles including geranyl acetate and citronellal 3 .
Read More: Geoponika: Agricultural Pursuits, translated from Greek by Thomas Owen in two volumes: this is volume 1 (London, 1805) (Internet Archive)
Plants have also been used for centuries in the form of crude fumigants where plants were burnt to drive away nuisance insects and later as oil formulations applied to the skin or clothes which was first recorded in writings by ancient Greek, Roman and Indian scholars . Through the eons, several oils have also shown repellency against a variety of insects. It is likely that they work in several ways:
- by reducing short range attractive cues i.e. kairomones, water vapour and temperature 4 5 6 ;
- by reducing the evaporation and absorption of repellent actives due to the presence of long-chained fatty molecules;
- by containing fatty acids are known to be repellent to insects at high concentrations 7 .
In Europe and North America, there is a strong history of use of essential oils dating back to Ancient times. Essential oils are volatile naturally occurring, complex compounds characterized by a strong odour and are formed by plants as secondary metabolites. An interesting, less known fact is that almost all the plants used as repellents are also used for food flavouring or in the perfume industry. Many commercial repellents contain several plant essential oils either for fragrance or as repellents including peppermint, lemongrass, geraniol, pine oil, pennyroyal, cedar oil, thyme oil and patchouli.
The oil is used extensively as a source of perfumery chemicals such as citronellal, citronellol and geraniol. Research has shown geraniol to be an effective plant-based mosquito repellent.
Active Compounds: C. winterianus essential oil is rich in citronellal, geraniol and citronellol. There are other constituents like citronellyl acetate, L-limonene, ellemol and other sesquiterpene alcohols present in citronella 8
Neem oil is a vegetable oil pressed from the fruits and seeds of the neem (Azadirachta indica), an evergreen tree which is endemic to the Indian subcontinent. Azadirachtin is the most well-known and studied triterpenoid in neem oil. Nimbin is another triterpenoid which has been credited with some of neem oil’s properties as an antiseptic, antifungal, antipyretic.
Active Compounds: Azadirachtin, Nimbin, Nimbidin, Nimbidol, Sodium nimbinate, Gedunin, Salannin, Quercetin 9 . Neem oil has a wide range of beneficial properties for your beloved pet:
- Relieves dry skin and improves general skin health;
- Soothes itchiness, redness and irritation of skin;
- Has anti-bacterial, anti-fungal and antiseptic properties;
- Can be used to help repel bugs by spraying on fur and bedding;
- NON TOXIC and biodegradable;
- Natural, pleasant smell
Lavandula angustifolia (Lamiaceae) is also known as Lavender, True Lavender, Garden Lavender, Lavanda, Lavandula. It is an evergreen, perennial shrub. Essential oil is used in aromatherapy in treatments of anxiety, nervousness, mental stress, insomnia and fatigue. Lavender oil is also an antiseptic and can be used for wound disinfection. It is also useful in treatment of alopecia areata, fungal infections, acne and eczema. Used internally, in form of a tea, lavender is used as a mild sedative and antispasmodic.
Active Compounds: linalool, linalyl acetate, cineol, pinene, limonene, geraniol, borneol, tannins 10 . Lavender has many uses and benefits:
- Can be used to help repel bugs
- Aroma provides a protective barrier around the animal
- Calming and soothing
- Natural pleasant smell
- NON TOXIC and biodegradable
Geraniol, derived from plants such as geraniums and lemongrass; is an extracted plant oil. It contains over 67 active compounds! Developed by Dr Jerry Butler in the late 90’s, an Entomologist from the University of Florida’s Institute of Food and Agricultural Sciences, this natural repellent provides protection from mosquitoes, house flies, stable flies, horn flies, cockroaches, fire ants, fleas, gnats, dog ticks, and lone star ticks. Plants containing the active compounds have the natural ability to repel insects. Geraniol is the primary part of rose oil, palmarosa oil, and citronella oil. It also occurs in small quantities in geranium, lemon, and many other essential oils. Geraniol has been considered a revolutionary insect repellent ingredient since 1999 . It has a variety of uses:
Read More: UF Entomologist Develops Safe, Effective Alternative To Deet Insect Repellents, (UF News)
- Can be used to help repel bugs;
- Aroma provides a protective barrier around animal;
- Can have anti-bacterial properties;
- Natural pleasant smell;
- NON TOXIC and biodegradable
Articles and Videos
- Insect repellent plants traditional usage practices in the Ethiopian malaria epidemic-prone setting: an ethnobotanical survey (PubMED);
- Repellency of powdered plant material of the Indian neem tree, the Labrador tea, and the sweet-flag, to some stored product pests. (CabDirect);
Safest Heartworm and Flea Prevention For Dogs
A Safe and Natural Pest Repellant for Pets!
Dr. Becker’s Facebook Live Presentation on Fleas, Ticks and Allergies
Are Flea Treatments Safe For Dogs and Cats
References and Research
- 1.Maia MF, Moore SJ. Plant-based insect repellents: a review of their efficacy, development and testing. Malar J. March 2011. doi:10.1186/1475-2875-10-s1-s11
- 2.Pichersky E, Gershenzon J. The formation and function of plant volatiles: perfumes for pollinator attraction and defense. Curr Opin Plant Biol. 2002;5(3):237-243. doi:10.1016/s1369-5266(02)00251-0
- 3.Carey A, Wang G, Su C, Zwiebel L, Carlson J. Odorant reception in the malaria mosquito Anopheles gambiae. Nature. 2010;464(7285):66-71. doi:10.1038/nature08834
- 4.Eiras AE, Jepson PC. Responses of female Aedes aegypti (Diptera: Culicidae) to host odours and convection currents using an olfactometer bioassay. Bull Entomol Res. June 1994:207-211. doi:10.1017/s0007485300039705
- 5.Davis E, Bowen M. Sensory physiological basis for attraction in mosquitoes. J Am Mosq Control Assoc. 1994;10(2 Pt 2):316-325. https://www.ncbi.nlm.nih.gov/pubmed/8965085.
- 6.WRIGHT R, KELLOGG F. Response of Aedes aegypti to moist convection currents. Nature. 1962;194:402-403. doi:10.1038/194402a0
- 8.Wany A, Jha S, Nigam V, Pandey DM. Chemical analysis and therapeutic uses of citronella oil from Cymbopogon winterianus: A short review. International Journal of Advanced Research. 2013;1:504-521. https://www.researchgate.net/publication/304488601_Chemical_analysis_and_therapeutic_uses_of_citronella_oil_from_Cymbopogon_winterianus_A_short_review.
- 9.Djenontin TS, Wotto VD, Avlessi F, Lozano P, Sohounhloué DKC, Pioch D. Composition of Azadirachta indica and Carapa procera (Meliaceae) seed oils and cakes obtained after oil extraction. Industrial Crops and Products. July 2012:39-45. doi:10.1016/j.indcrop.2012.01.005
- 10.Lu H, Li H, Lu H. Chemical composition of lavender essential oil and its antioxidant activity and inhibition against rhinitis-related bacteria. African Journal of Microbiology Research. 2010;4:309-313. https://academicjournals.org/journal/AJMR/article-abstract/AFB8DA511807.