Mosquitos, Sandflies and Repellents

Insect Vectors of the Caribbean

The Caribbean is known for its crystal beaches, lush vegetation, picturesque sunsets and relaxed living. Yet, it is home to a range of insect Arthropods that carry and transmit diseases (Vectors). Mosquitos, Sandflies and Ticks are some of the region's most noteworthy Arthropod Vectors. This blog will explore these vector-borne disease carriers, the pathogens they spread, associated diseases such as Dengue, Zika, Chikungunya and their negative impacts on human health. Noteworthy preventative measures will be presented, including conventional repellent actives such as DEET and insecticides like Permethrin, comparing their efficacies, health safety and sustainability profiles. In contrast, Biobased Repellents will be highlighted, leveraging nature-based organic compounds found in botanicals like Neem, Citronella, Eucalyptus, and Rosemary. Finally, we will propose Bee Propolis, a powerful resin used by bees to deter and trap common hive pests, as a potential repellent active.

Mosquitoes, A Caribbean Nuissance

Diagram of Mosquito Anatomy, Arizona State University. Source: https://askabiologist.asu.edu/mosquito-anatomy

Mosquitoes are common pests that are found in many regions around the world, particularly in warm and humid climates. These small flying insects are not just a nuisance but pose significant health risks to humans and animals alike. Their presence is often associated with stagnant water sources, where they breed and lay their eggs, leading to increased populations during certain seasons. The health risks associated with mosquitoes are primarily due to their role as Vectors for various diseases. Mosquitoes are known to transmit serious illnesses such as Malaria, Dengue Fever, Zika Virus, West Nile Virus, and Chikungunya, among others. Each of these diseases can have severe consequences for human health, ranging from mild flu-like symptoms to life-threatening conditions. For example, Malaria continues to be a major public health challenge in many tropical and subtropical regions, infecting millions of people each year and resulting in significant mortality rates, particularly among children. In addition to the direct health impacts, the presence of mosquitoes can also lead to economic burdens on communities. The costs associated with healthcare, prevention measures, and loss of productivity due to illness can be substantial. Many regions invest heavily in mosquito control programs, which may include the use of insecticides, the release of genetically modified mosquitoes, and public health campaigns aimed at educating people on how to reduce mosquito breeding sites around their homes. Furthermore, the social implications of mosquito-borne diseases are profound. Outbreaks can disrupt daily life, affect travel and tourism, and strain healthcare systems. Communities may experience heightened anxiety and fear, especially during peak transmission seasons.

Preventive measures are crucial in managing mosquito populations and reducing the risk of disease transmission. Individuals are encouraged to take steps such as using insect repellent, wearing long-sleeved clothing, and installing screens on windows and doors to keep mosquitoes out of living spaces. Additionally, eliminating standing water in yards and neighborhoods can significantly reduce mosquito breeding sites. Understanding the risks they pose and implementing effective control strategies is essential for protecting communities from the diseases they carry.

The Lifecycle of A Mosquito (Culicidae)

The lifecycle of a mosquito is a fascinating journey that encompasses several distinct stages, each with its own unique characteristics and requirements. These stages include the Egg, Larval, Pupal, and Adult stages. From inception to maturity, the lifecycle begins with the Egg Stage, during which female mosquitoes lay their eggs in or near water sources. These eggs are often deposited in clusters, known as Rafts, floating on the surface of the stagnant water. Depending on the species, the eggs can vary in colour and shape, with some being black or brown and others appearing more translucent. The choice of laying site is crucial, as the eggs require a moist environment to survive and hatch. After a few days, depending on environmental conditions such as temperature and humidity, the eggs will hatch into larvae. Once the eggs hatch, the mosquito enters the Larval Stage, which is characterized by its aquatic lifestyle. Larvae, commonly referred to as "wigglers", are elongated and have a distinct head and tail. They feed on organic matter, algae, and microorganisms in the water, which provides the necessary nutrients for their growth. This stage can last from several days to a few weeks, depending on factors such as food availability and water temperature. During this time, larvae shed their skin multiple times as they grow larger by a process called Moulting.

Lifecycle schematic of a Mosquito, Mosquito Hero. Source: https://mosquitohero.com/en-ca/blog/mosquito-life-cycle-explained

Following the larval stage, the mosquito transforms into the Pupal Stage. This stage is a transitional phase where the larvae undergo significant changes in preparation for adulthood. Pupae, often called "tumblers", are typically comma-shaped and do not feed. Instead, they float on the water's surface, where they are more vulnerable to predators. Inside the pupal casing, the mosquito undergoes Metamorphosis, developmental changes in body structure as it becomes an adult. This stage usually lasts from a couple of days to a week, influenced by environmental conditions.

The final growth stage is the Adult Stage, characterized by their slender bodies, long legs, and wings, thereby completing the mosquito lifecycle. Adult mosquitoes are Males and females can be distinguished by their physical features; males tend to have bushy antennae, while females have a streamlined, minimal appearance. After emerging, adult mosquitoes typically rest for a short period to allow their wings to dry and expand before they take their first flight. Female mosquitoes require a blood meal to develop their eggs, motivating them to seek out blood hosts, including humans and animals. Males, on the other hand, primarily feed on nectar and plant juices. The adult stage can last for several weeks to months, depending on environmental factors and the availability of food sources. During this time, female mosquitoes will continue to lay eggs, thus perpetuating the lifecycle. Understanding this lifecycle is crucial for developing effective strategies for mosquito control and management, especially in areas where mosquitoes are vectors for diseases.

Specific to the Caribbean region, biodiversity studies, particularly of the Dutch Antilles, reveal a wide array of mosquito species. Among the numerous species, Culex quinquefasciatus, Aedes mediovittatus, and Aedes aegypti stand out as the most prevalent, particularly in urban and suburban environments.

Culex quinquefasciatus

• Disease Transmission: West Nile virus, Lymphatic Filariasis, St. Louis Encephalitis

  
  

• Habitats: Drainage ditches, septic tanks, cesspools, and urban water collections

  
  

• Feeding Behaviour: Primarily a nocturnal feeder, actively biting during the evening and night. Opportunistic feeding behaviour targeting humans, birds, and other animals.

  
  

Image of Culex quinquefasciatus. Wikipedia, at: https://en.wikipedia.org/wiki/Culex_quinquefasciatus

Commonly referred to as the Southern House Mosquito, Culex quinquefasciatus, is a species of mosquito that is prevalent across Caribbean ecosystems. This mosquito species has adapted well to the warm, humid climates typical of the tropical region. C. quinquefasciatus thrives in a variety of environments, especially in stagnant water bodies such as ponds, marshes, and artificial containers like discarded tires and clogged gutters. These stagnant waters serve as ideal breeding grounds for C. quinquefasciatus, where females lay their eggs in clusters, for quick population expansion. Beyond their sheer numbers and regular nuisance, they pose significant public health risks.

As vectors, they are capable of transmitting various pathogens that can lead to serious diseases in humans. Notably, they are known to carry the West Nile Virus (WMV), and the St. Louis Encephalitis Virus. The transmission of this virus typically occurs when an infected mosquito bites a human, introducing the virus into the bloodstream. In addition to the West Nile virus, Culex quinquefasciatus is also a vector for Filariasis, a parasitic disease caused by filarial worms. This disease can lead to severe complications, including Lymphedema and Elephantiasis, which can greatly affect an individual's quality of life. The transmission of these filarial worms occurs through the bite of an infected mosquito, making the control of mosquito populations crucial in preventing outbreaks of this debilitating disease. Efforts to manage the populations of Culex quinquefasciatus often include environmental management strategies, such as eliminating stagnant water where mosquitoes breed, as well as the use of insecticides and public education on protective measures. [1-4]

Aedes mediovittatus

• Disease Transmission: Dengue and Chikungunya (under specific conditions).

  
  

• Habitats:  Mangroves, urban gardens, stagnant water.

  
  

• Feeding Behaviour: Daytime feeder, peak feeding times are early mornings and late afternoons. Bloodmeals from humans and dogs mainly.

  
  

Photo of Aedes mediovittatus, iNaturalist, ©Kerry Lewis. Source: https://uk.inaturalist.org/taxa/1030293-Aedes-mediovittatus

Known as the 'Caribbean tree hole mosquito', Aedes mediovittatus is a mosquito species native to the Caribbean that is both a nuisance biter and a vector of viral diseases. Found predominantly in areas with dense vegetation, this mosquito is known to inhabit regions ranging from tree trunk holes to mangroves to urban gardens where stagnant water serves as their breeding ground. As a diurnal (daytime) feeder, this mosquito species rises and sets with the sun, with peak feeding in early mornings and late evenings. While it is not as well-studied as Aedes aegypti or Aedes albopictus, research indicates Ae. mediovittatus could potentially transmit arboviruses (insect viruses), including Dengue and Chikungunya, under specific conditions. Its adaptability to urban and rural environments poses challenges for effective vector control in the region. Unlike other Aedes species, Ae. mediovittatus often displays idiosyncratic behaviours, such as feeding chiefly on human and dog blood meals, to a lesser extent on cats, cows, horses, rats, pigs, goats, sheep, and chickens. [3,4]

Aedes aegypti

• Disease Transmission: Dengue, Zika, Chikungunya, and Yellow Fever

  
  

• Habitats:   Urban and peri-urban, small stagnant water containers

  
  

• Feeding Behaviour: Daytime feeder, peak feeding times are early mornings and late afternoons. Mainly bloodmeals from human hosts.

  
  

Photo of Aedes Aegypti, ©Caribbean Public Health Agency (CARPHA). Source: https://caribbeanmosquitoweek.carpha.org/Home/CMAW-2022

Also known as the 'Yellow Fever mosquito', Aedes aegypti is one of the most notorious vectors of Zika, Chikungunya, Dengue, and Yellow Fever . Speculated to have originated in Africa, later spreading to the western tropics through the transatlantic slave trade. This species thrives in tropical and subtropical climates, breeding in artificial containers like discarded tyres, buckets, and flower pots with stagnant water. The adaptability of Ae. aegypti to urban environments has facilitated its widespread distribution across the Caribbean islands. In 2024, the region experienced a significant surge in dengue cases, with over 12 million reported in the Americas, including the Caribbean, marking a substantial increase from previous years (PAHO, 2024). Females are responsible for biting to obtain blood meals for egg production. This alarming rise underscores the critical need for effective vector control measures and insect repellent use for public health interventions to mitigate the impact of its spread throughout the region. [4-7]

Aedes albopictus

• Disease Transmission: Dengue, Zika, Chikungunya, (occasionally Yellow Fever).

  
  

• Habitats:   Urban to rural settings, breeds in natural and artificial containers, such as tree holes, bamboo stumps, flower pots, old car tyres.

  
  

• Feeding Behaviour: Peak biting occurs in the early morning and late afternoon. It is an opportunistic feeder that targets humans, domestic animals, and wildlife.

Photo of Aedes albopictus, ©European Center for Disease Prevention and Control (ECDC). Source: https://www.ecdc.europa.eu/en/disease-vectors/facts/mosquito-factsheets/aedes-albopictus 

Commonly known as the 'Asian Tiger Mosquito', is an invasive species that has established populations in the Caribbean. Recognized for its distinctive black-and-white striped pattern, this mosquito is a competent vector of several arboviruses, including Dengue, Zika, Chikungunya and Dilogilariasis. Unlike Ae. aegypti, Aedes. albopictus thrives in both urban and rural environments, breeding in natural and artificial containers such as tree holes, discarded tyres, and water-filled containers. Ae. albopictus is primarily a daytime feeder, with peak biting at dawn and dust. It is an opportunistic feeder, targeting humans, domestic animals, and wildlife. This cross-species feeding behaviour increases the likelihood of transferring animal-based diseases to us humans, a phenomon known as Zoonosis or Zoonotic Disease. Unlike other mosquito species, Ae. albopictus is a persistent biter and feeds multiple times on a single blood meal, thereby increasing its tendency to transmit Zoonotic diseases. Its prevalence in the Caribbean highlights the need for robust vector surveillance, control measures and the use of effective repellent formulations. [7]

Anopheles albimanus

• Disease Transmission: mainly Malaria.

  
  

• Habitats: thrives in diverse habitats, coastal lagoons, mangroves, stagnant water.

  
  

• Feeding Behaviour: twilight and nighttime feeder, with peak biting activity occurring during the early evening and early morning hours. Primarily feeds on humans, lesser extent on livestock and other mammals.

Photo of Anopheles albimanus by ©Penn State. Source: https://www.inaturalist.org/taxa/259056-Anopheles-albimanus

Anopheles albimanus is one of the transmitters of Malaria in the Americas and parts of the Caribbean. This mosquito species thrives in various habitats, from coastal lagoons and mangroves to inland stagnant water bodies. Unlike many other Malaria vectors, An. albimanus is highly adaptable and can survive in both freshwater and brackish environments. It is primarily a Crepuscular (twilight) and Nocturnal (night) feeder, with peak biting during evening and early morning hours. While its primary host is humans, An. albimanus can feed on livestock and other mammals. Anopheles albimanus is critical in transmitting Plasmodium vivax and Plasmodium falciparum, parasites responsible for Malaria, making it a significant public health concern. Its role as a vector underscores the need for effective mosquito control strategies, such as larval habitat management, insecticide-treated nets, and indoor residual spraying, and topical repellents. [8]

Sandflies (Psychodidae)

• Disease Transmission: Leishmaniasis and Sand Fly Fever.

  
  

• Habitats: Swamps, mangroves, sandy areas, and forested regions.

  
  

• Feeding Behaviour: Active from dusk to dawn, their stealthy and persistent biting behaviour targets humans and animals to obtain blood meals

  
  

Photo of Phlebotamine Sandfly, © European Centre for Disease Prevention and Control (ECDC). Source: https://www.ecdc.europa.eu/en/disease-vectors/facts/phlebotomine-sand-flies

Lifecycle schematic of a Sandfly, Nature. Source: https://www.nature.com/articles/s42003-022-03240-z

Phlebotomine Sandflies in the Caribbean are small, blood-feeding insects that are vectors for diseases such as Leishmaniasis and Sandfly fever, caused by Leishmania parasites and Phleboviruses, respectively. These flies thrive in habitats near swamps, mangroves, sandy areas, and forested regions, often hiding in cracks, crevices, and under rocks during the day. Considered by many as the bane of Caribbean living, sandflies are active from dusk to dawn. Their stealthy and persistent biting behaviour targets humans and animals to obtain blood meals required for egg production. The saliva of sandflies contains anticoagulant and immunomodulatory compounds that facilitate feeding while causing irritation and allergic reactions in the host. The skin of bitten humans appears red-spotted and swollen, with an itchy irritation. Caribbean residents with compromised skin barriers, including Ezcematic and Fish Scale Skin, are often targets of these itchy nuisances, causing sores and bruises from over-scratching. Their preference for specific habitats makes them a significant concern for public health, particularly in areas with high rates of Leishmaniasis transmission also causing skin sores. Effective, broad-spectrum repellents are needed in the Caribbean to ward off these pesky, potentially dangerous critters. [10]

Ticks (Ixodida)

• Disease Transmission: Lyme disease, Anaplasmosis, and Babesiosis.

  
  

• Habitats: Grasslands, forests, livestock enclosures, and mangroves.

  
  

• Feeding Behaviour: Targets hidden, hard-to-reach regions areas of their hosts, especially of dogs, cats, cattle and the hairlines of humans.

  
  

Photo of Blacklegged Tick, Caribbean News Global, © Jim Gathany. Source: https://caribbeannewsglobal.com/protect-yourself-from-tick-bites-this-summer-2/

Ticks in the Caribbean are significant ectoparasites, outer surface parasite, and vectors of Zoonotic diseases that affect both humans and animals. Common tick-borne diseases in the region include Lyme Disease caused by Borrelia bacteria; Anaplasmosis from the bacteria Anaplasma phagocytophilum; and Babesiosis caused by the parasite Babesia. The tropical environment of the Caribbean provides ideal habitats for ticks, like grasslands, forests, livestock enclosures, and mangroves. These habitats have biodiverse hosts such as livestock, birds, and small mammals. Ticks are obligate blood feeders, meaning that they specifically need blood, attaching to hosts and feeding over extended periods, during which pathogens can be transmitted. Their feeding behaviour targets hidden areas of their hosts, especially hard-to-reach regions of animals like underarms, back, behind the ears and tails, making them difficult to dislodge. Due to their role in disease transmission, ticks pose a public health risk, particularly for individuals working in agriculture, forestry, or outdoor recreation in the Caribbean. [11]

Harvest Mites also known as Chiggers (Trombiculidae)

• Disease Transmission: No known transmission of disease (within the Caribbean & North America)

  
  

• Habitats:  Humid and warm environments

  
  

• Feeding Behaviour: they can attach to the skin of humans and animals to feed, often around skin folds such as the ankles, waist, or underarms. Feeding behaviour lasts several hours

Scanning Electron Microscope image of a Yellow Mite, © USDA.gov. Source: https://infinitespider.com/introduction-chiggers/

Harvest Mites, are in fact the larval stage of mites in the Trombiculidae family. These ectoparasites are also found in the Caribbean apart from North America, where they are referred to as 'Chiggers'. Their ideal habitats are grasslands, forests, and sandy regions. Harvest mites are sometimes confused for Ticks. But Mites are a thousand times smaller than ticks, 0.3 microns (µm) compared to 3 millimeters (mm), respectively.

A microscope like the Scanning Electron Microscope is necessary to see mites, on the other hand, a basic Light Microscope makes ticks effortlessly visible. While Mites do not transmit disease directly, their bites can cause intense itching, inflammation, and allergic reactions due to their digestive enzymes which they inject into the skin for continuous feeding. Chiggers prefer humid and warm environments, where they can attach to the skin of humans and animals to feed, often around skin folds such as the ankles, waist, or underarms. The feeding behaviour of Chiggers typically lasts several hours, after which they detach to continue their life cycle. While bites from western Chiggers, including the Americas and Caribbean, typically do not transmit disease, bites from Chiggers can lead to secondary infections if scratched excessively. Skin bites have an onset of local redness, swelling and itchy lasting for days. The presence of chiggers in rural and outdoor areas makes them a nuisance for individuals. [12]

Preventative Measures For Insect Vectors

Preventative strategies for insect vector-borne diseases in the Caribbean should focus on reducing exposure to disease-carrying vectors and lowering the opportunity of creating breeding grounds. Effective measures include using insect repellents, wearing protective clothing, sleeping under insecticide-treated bed nets and leveraging window and door mesh screens. Environmental management is crucial, eliminating standing water sources where mosquitoes breed, maintaining clean gutters, and covering water storage containers. Community-based programs emphasizing public awareness and education about vector control help foster a culture of reducing insect vector-borne transmission rates. Additionally, government-led initiatives, including regular insecticide spraying and health surveillance, further bolster preventative measures against diseases like Dengue, Zika, and Chikungunya (PAHO, 2023).

Common Topical Repellents

Chemical repellents like DEET, Permethrin and Picaridin have long been the mainstay for preventing vector-borne diseases. First developed in the mid-20th century, these compounds are effective against a wide range of insects.

DEET (N,N-Diethyl-Meta-Toluamide)

• Petrochemical-based.

• Developed by the U.S. Army in 1946 for jungle warfare.

• Repellence between 2-12hrs (mosquitos, ticks, fleas, and flies)

• Works by confusing the mosquito's sense of smell.

• Literature reports on the health implications of DEET in adults and children show it to be benign when used appropriately.

• Could be slightly toxic to birds, fish, and aquatic invertebrates, practically nontoxic to mammals

  
  

DEET is one of the most popular insect repellents with a fascinating origin story. The compound was developed by the U.S. Army in 1946 in response to the urgent need to protect soldiers from insect-borne diseases (Malaria, Dengue, and Typhus) during World War II and subsequent military operations in tropical regions like Vietnam. These diseases severely impacted the health of soldiers and operational efficiency. DEET is a synthesized compound assembled on top of a platform petrochemical known a Toluene. Its ability to repel a wide range of biting insects, including mosquitoes, ticks, fleas, and flies, made it an indispensable tool in both military and civilian contexts.

Chemical Structure of DEET. Source: https://en.wikipedia.org/wiki/DEE

Initially, DEET was made available exclusively to the U.S. military in its early days. However, recognizing its potential for broader public health applications, the U.S. Environmental Protection Agency (EPA) registered its use for the civilian population in 1957. Its widespread adoption coincided with increasing global travel, outdoor recreational activities, and the rising prevalence of vector-borne diseases. DEET’s mechanism of action is unique, the compound does not kill insects directly but blocks their olfactory receptors, making it difficult for biting insects to smell blood hosts. Its mechanism of action together with its long-lasting efficacy contributed to DEET's dominance in the market for decades. Literature reports on the health implications of DEET in adults and children show it to be benign or low risk if used appropriately, 5%-30%; when misused, users report skin irritation, dizziness and eye irritation. A disadvantage of DEET is that it can damage clothes and personal items by degrading fabric materials like spandex, rayon latex, and elastic, as well as plastics, rubber, and vinyl found in outdoor items like sunglasses and watchbands. The US Environmental Protection Agency (EPA) suggests that DEET's bioaccumulation in the environment could be slightly toxic to birds, fish, and aquatic invertebrates and practically nontoxic to mammals. [13-17]

Permethrin

• Synthetic compound made to resembled a natural compound found in Chrysanthemum flowers

• Insecticide that kills mosquitos mites, ticks (not mammals like Humans)

• Can cause skin irritation or, in rare cases, neurological symptoms in sensitive individuals.

• Highly toxic to aquatic life, including fish and invertebrates

  
  

Permethrin is a synthetic chemical widely used as an insecticide. It is part of the pyrethroid family, synthetic derivatives of natural Pyrethrins found in Chrysanthemum flowers. Pyrethroids are highly effective insecticides due to their ability to disrupt the nervous system of insects, causing paralysis and eventual death. Permethrin has been widely adopted for both agricultural and public health purposes, including crop protection, livestock pest management, and the prevention of vector-borne diseases. Permethrin can be used to treat clothing, mosquito nets, and outdoor gear to repel and kill mosquitoes, ticks, and other arthropods. It is particularly effective in controlling species like Aedes aegypti, Anopheles mosquitoes, and Ticks that spread diseases such as Malaria, Dengue, and Lyme disease. Its long-lasting activity on treated materials provides prolonged protection, making it a preferred option in vector control programs in tropical and subtropical regions.

Chemical structure of Permethrin. Source: https://en.wikipedia.org/wiki/Permethrin

Chemically, permethrin works by targeting the sodium channels of insect neurons. It delays the closure of these channels, causing prolonged nerve excitation and ultimately paralysis. This mode of action is highly specific to insects, making permethrin relatively safe for humans and mammals when used appropriately. However, caution is necessary, as exposure to high levels can cause skin irritation or, in rare cases, neurological symptoms in sensitive individuals. Despite its effectiveness, Permethrin poses environmental challenges. It is highly toxic to aquatic life, including fish and invertebrates, and can accumulate in ecosystems if improperly disposed of or overapplied. Its environmental and health implications necessitate judicious use. [18,19]

Picaridin, otherwise known as Icaridin and KBR3023

• Also known as "Icaridin" or "KBR 3023"

• Synthetic compound designed to resemble a natural compound found in pepper

• Introduced in the late 1990s

• Repellence between 8-12hrs (mosquitos, flies, ticks, chiggers, and sandflies)

• Less odorous alternative to DEET while maintaining efficacy

• Less likely to cause irritation or allergic reactions even when used at higher than recommended concentrations (opposed to DEET)

  
  

Picaridin, also known as Icaridin or KBR 3023, is a synthetic insect repellent developed in the 1980s and introduced to the market in the early 2000s as a 'safer' alternative to DEET. Chemically assembled to resemble a natural compound found in the pepper plant, Piperidine, Picaridin provides long-lasting protection against a wide range of biting insects including mosquitoes, Flies, Ticks, Chiggers/Mites, and Sandflies. Offering up to 8–12 hours of protection depending on the concentration, Picaridin is a highly effective and reliable repellent. One of Picaridin's major advantages is its supposedly skin-friendly nature. Unlike DEET, it is less likely to cause irritation or allergic reactions even when used inappropriately or in higher concentrations than recommended.

Chemical structure of Picaridin. Source: https://www.carlroth.com/be/en/pesticides/picaridin/p/233t.1

Furthermore, it is odourless, leaving no greasy or sticky residue. Picaridin may require reapplication after heavy sweating or water exposure and, in some cases, might not perform as well as DEET against specific species. Picaridin does not degrade plastics, rubber, or synthetic materials like DEET, making it safer for outdoor gear and clothing use. Its safety profile is largely benign, with approval for use on children as young as two months old and during pregnancy. Picaridin is biodegradable and considered less toxic to aquatic ecosystems than DEET. Picaridin’s combination of effectiveness, user comfort, and environmental benefits has made it a preferred choice for those seeking protection from vector-borne diseases, underscoring its value in global mosquito and tick-bite prevention strategies. [20]

Consumer Preference for Skin Safe, Biodegradable Repellents

The Sustainability and Wellness movements have driven innovation in nature-based repellents, promoting natural ingredients that prioritize health and environmental safety. These products align with the global agenda of reducing potentially toxic petrochemicals in consumer products. Traditional chemical repellents, such as DEET and Permethrin, have long been effective in protecting against disease-carrying insects but are associated with significant environmental and health concerns. These include potential toxicity to non-target organisms, persistence in aquatic ecosystems, and adverse effects on human skin and neurological health. As global awareness of these issues grows, there is an increasing demand for safer, eco-friendly alternatives that offer comparable protection without the associated risks.

The 17 Sustainable Development Goals (SDGs). My Climate, at: https://www.myclimate.org/en/information/faq/faq-detail/what-are-the-sustainable-development-goals-sdgs/

Biobased repellents from natural plant extracts and renewable resources represent a promising solution. Essential oils such as Citronella, Eucalyptus, Neem, Lemongrass and Thyme, have demonstrated somewhat effective repellent properties, targeting the same vectors responsible for diseases like Malaria, Dengue, and Zika. These natural alternatives are biodegradable and typically non-toxic to pollinators, aquatic life, and humans, making them ideal for environmentally conscious consumers. Balanced and wisely crafted formulations that leverage organic repellent compounds could enhance longevity, range and overall product efficacy. This shift also aligns with Sustainable Development Goals (SDGs) using renewable resources, minimizing environmental footprint and contributing to the circular economy.

Bee Propolis For Biomimetic Repellency

Biomimetics, or Biomimicry, is the emulation of nature to solve human problems.

Bee Propolis, also known as "bee glue", is a resinous substance honeybees collect from plant exudates. Prop·o·lisis is of Greek aetiology, pro meaning "in defence of" and polis meaning "community”. Put together, Propolis translates to Hive Guardian. Classified as an oleoresin with essential oil and waxy-resin components, bee propolis is a natural sealant in hives, protecting against microbial invasion, temperature fluctuations, and intruding pests. Recent research has highlighted its potential as a natural insect repellent, attributed to its complex chemical composition, which includes Flavonoids, Phenolic acids, Esters, Terpenoids, and Essential oils. These bioactive compounds are responsible for the Antimicrobial, Antifungal, and repellent properties of bee propolis. Research indicates that Propolis exhibits significant repellent properties against insect pests, including mosquitoes, ticks, mites and termites.

Photo of Bee Propolis in a Langstroth Hive. Source: https://www.comvita.co.nz/blog/How%20bee%20propolis%20protects%20the%20health%20of%20the%20hive

A study published in the Technoscience Journal for Community Development in Africa (2020) examined bee Propolis as a protectant against insect pests such as the Maize Weevil (Sitophilus zeamais) and Cowpea Weevil (Callosobruchus maculatus) that damage stored grains in Nigeria. Further investigations into bee Propolis as a repellent have also shown its efficacy against mosquitoes. A study published in the South Carolina Junior Academy of Science (2023) assessed the effect of propolis concentrations on the repellency of Culex quinquefasciatus, a mosquito species prevalent in tropical regions. The findings indicated that higher concentrations of propolis resulted in increased repellency, suggesting its potential as a natural mosquito repellent. These studies highlight the promising role of bee propolis as a biobased, sustainable repellent, aligning with the global movement toward reducing harmful chemicals and promoting environmental health. [21-23]

Bee Propolis in a Biobased Insect Repellent Formula

Biobased Insect Repellent with Bee Propolis. © Isle Bee Well Inc 

Bee propolis, together with extracts of known natural repellents like Essential oils of Eucalyptus, Neem, Rosemary, Citronella has been leveraged to formulate a balanced natural insect repellent spray. This insect repellent also features soothing Aloe vera together with hydrating Panthenol (Vitamin B5), redness-reducing Alpha-bisabolol and skin repairing Alpha

Tocopherol (Vitamin E). Boasting on average, 6-8hrs of repellence, Isle Bee Well's insect repellent spray is a noteworthy option to ward off some tropical insect vectors.Transitioning to biobased repellents, ideally highlighting propolis extract aligns with our commitment to sustainability and wellness.

In Closing

Vector-borne insect diseases such as Dengue, Malaria, Zika, Chikungunya and Leishmaniasis pose major health risks. Efforts to prevent, and manage the spread of communicable vector-borne diseases, have taken many forms, insect repellent formulas, protective clothing, insecticide-treated bed nets, window and door mesh screens. Other actionable approaches have included emptying of stagnant water sources, awareness campaigns and public health education. Insect repellent formulas have been the go-to option, because of their convenience, relatively low cost and practicality. Consumer preference for safer, eco-conscious vector-borne insect repellent solutions is influencing the market strongly. This shift in consumer behaviour is largely driven by a growing awareness of public health risks associated with traditional insect repellent formulations derived from finite fossil resources. Everyday usage of conventional insect repellents, have correlated with allergic skin and respiratory reactions. Recently, the environmental impact of conventional insect repellents has come under scrutiny, prompting consumers to seek more sustainable options. Concurrently, insect repellent manufacturers are being nudged to reimagine their repellent formulas to be safe for people and the planet, spawning biobased product innovations. We at Isle Bee Well, we have leveraged Bee Propolis, along with local plant extracts for a skin-friendly, biodegradable insect repellent.

Samuel Jones

Bsc. Biological Sciences (Hons.)

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References:

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