Insect Repellents and Protection
Please read our Medical Disclaimer.
Biting and stinging bugs can be quite a nuisance. Bites are often itchy and annoying but can cause life threatening allergic reactions to some trekker and bites can transmit serious and even fatal diseases.
There are a lot of bugs out there that bite, sting and possibly transmit many diseases. Bite and stings can be a minor nuisance or create severe itchiness and local reactions or even cause severe and potentially deadly allergic reactions. Many diseases transmitted by bugs can be debilitating, fatal or cause severe disfigurement. Travelers should be aware of possible bugborne diseases in their areas of destination and take necessary precautions against any bugborne disease that may be present.
These can release venom with their sting and be quite painful. Some people will have a severe allergic reaction to certain stings, which can be life threatening. Trekkers with known severe allergic reaction, such as anaphylactic shock, should always are a bee sting kit with epinephrine.
Honey bees have a stinger that is able to be used just once, whereas other stinging insects can sting repeatedly. Swarms of angry stinging insects can cause great deal of discomfort or even be deadly to those caught in them. If you find yourself in a swarm of stinging insects, turn around and run as fast as you can. Avoid dropping anything you would like to keep, since you may not want to go back to this area.
Insect repellents don't work against stinging insects and you should avoid use of perfumes or scented lotions and brightly colored clothing. If you find a nest or hive near a campsite you plan to use long term, you may decide to relocate or if you are not concerned about karma, you should eradicate these potential problems with appropriate insecticides.
There are more than 2500 species of mosquitoes world-wide. They can be a constant source of annoyance and some travelers can have severe local reactions to bites. But more importantly, several species can transmit significant diseases such as West Nile virus, Yellow fever, Malaria, Dengue Fever, Filariasis, Encephalitis, Eastern Equine Encephalitis and Japanese Encephalitis.
Diseases such as malaria can be deadly and avoidance of mosquito bites in high risk areas should be taken seriously.
Sand flies are often referred to as No-See-Ums because of their small size. They can transmit Oroya fever, Leishmaniasis, pappataci fever virus, kala azar, Oriental sore, espundia, and bartonellosis.
Leishmaniasis is a pretty nasty disease. It can be fatal and/or severely disfiguring.
These Sub-Saharan flies have painful bite and are know to transmit African Trypanosomiasis (African Sleeping Sickness).
Black flies can have a nasty bite and in the tropics and subtropics can transmit filariasis which can cause elephantiasis.
Biting Midges (no-see-ums, punkies)
These are tiny little blood sucking flies that like wet areas. They are often referred incorrectly as sand flies in Australia. These transmit visceral filariasis.
These may carry eye worm.
Bot Flies (Dermatobia hominis)
Bot flies lay eggs on dirty clothing, laundry and dead or dying flesh of living people. They can also capture other flies, insects or ticks and glue eggs on their abdomens. In 5-15 days, the eggs hatch and embryos abandon its carrier when it comes in contact with a warm blooded host. Once on the host, the embryo either enters through a bite site from its carrier or it burrows through a hair follicle, break in skin or a skin fold. The larva forms a boil like pocket under the skin with an air hole and matures over the next many weeks and may be there for as long as 3 months.
Travelers with Bot Fly infestations may have a boil-like skin lesion and have a sensation of something moving under their skin. These are often misdiagnosed or dismissed by medical providers in the US and Europe.
Ticks, like mites, are actually arachnids (eight legs) and not insects (six legs). They can transmit many diseases including Lyme disease, African tickbite fever, Aneruptive fever, Australian spotted fever, Far Eastern spotted fever, Flinders Island spotted fever, Thai tick typhus, Lymphangitis associated rickettsiosis, Maculatum infection, Mediterranean spotted fevers, North Asian tick typhus, Oriental spotted fever, Queensland tick typhus, Rocky Mountain spotted fever, Sao Paulo exanthematic typhus, Minas Gerais exanthematic typhus, Brazilian spotted fever, Tick-borne lymphadenopathy (TIBOLA), Dermacentor- borne necrosis and lymphadenopathy (DEBONEL), Unnamed rickettsiosis, Q fever, Ehrlichosis and Anaplasmosis.
Tick infested areas should be avoided if possible. If you end up traveling through a tick habitat, you should perform frequent body checks to remove any ticks.
Ticks often respond to different repellents than those often used for mosquitoes. DEET has questionable efficacy against ticks and doesn't stop them from walking across treated skin onto untreated skin. DEET also offers longer protection on clothing than it does on skin. Permetherin seems to offer a considerable amount of protection against ticks.
Mites can transmit Rickettsialpox and Scrub typhus.
Scabies is caused by a small mite that burrows under the skin and causes an unbearable itch. You usually need prolonged physical contact with and infect person or infested clothing or bedding.
Chiggers are larvae of harvest mites that like to hang out in wet grass, near river banks, and under trees and bushes. Once on you, the search for protected areas, such as around ankles, under socks, waistline, under belts and elastic bands of underwear etc. There, they pierce your skin and release digestive enzymes. This causes a really nasty rash and horrible itch. Scratching can later lead to an infection. Chiggers also transmit Scrub typhus (Tsutsugamushi). Repellent should be used on shoes, socks, ankles, legs and pant cuffs to deter or kill chiggers.
Fleas can transmit Plague, Epidemic typhus, Sylvatic typhus, Cat flea rickettsiosis, Murine typhus and Cat-scratch disease.
Chigoe fleas are endemic to Central America and West Africa. Female Chigoe fleas are know to penetrate the skin around toes and then swell up with eggs. This causes a significant amount of inflammation and ulceration that can lead to infection and even gangrene. Trekkers should avoid walking with uncovered feet in Chigoe habitats.
Lice comes in a couple of different forms as is just nasty. They can also transmit Epidemic typhus, Sylvatic typhus and Trench fever.
These are transited by intimate contact with other or sharing of clothing.
Assassin Bugs (aka Kissing Bugs)
Assassin bugs are pretty mean little critters that like to hide in the wall and attack you at night. Besides their nasty bite, they can transmit American Trypanosomiasis (Chagas’ disease).
You may want to sleep with the lights on and move the bed away from the wall in areas where these guys live.
These live in cracks in the wall, under wallpaper and in bed frames. They like to come out when its dark and feed on exposed skin and sleeping victims. Don't let them bite.
You may want to sleep with the lights on and move your bed away from the walls where they hide.
There are many poisonous and nonpoisonous ants in the world. The poisonous variety can can have some pretty painful bites that leave blisters. There are reported cases of people who have received enormous numbers of bites (from jumping into an ant hill) from fire ants and subsequently died.
One traveling in areas with poisonous ants should be aware of where they sit or walk and avoid areas infested with ants.
There are many insect repellents, insecticides and various systems to fight bugs. Backpacker beware - many of these systems don't work or may actually be dangerous to use - even if used as directed. In the US, most insecticides are regulated by the EPA. This means that they must be registered by the EPA and are not overly harmful if used as directed. Being registered by the EPA does not mean that a particular product is effective by any means. In fact, many EPA registered products are more or less completely useless. Also of note, many herbal product do not have to mean any EPA guidelines to be sold or used as a pest repellent.
In countries outside of the US, Canada and Europe still routinely use DDT and other pesticides that are know to be hazardous to human (as well as non-human) health. Care should be taken with selecting insect repellents and pesticides abroad.
There are a few synthetic bug juices out there that have been used for years and have shown efficacy in the lab as well as in the field.
DEET (Meta-N,N-diethyl toluamide or N,N-diethly-3-methyl-benzamide)
DEET is the industry standard for insect repellants and is backed by the CDC. It repel many biting pests such as mosquitoes and ticks, including ticks that may carry Lyme disease. DEET is believed to work by blocking insect receptors used to detect carbon dioxide and lactic acid, which are used to find its host. This, in effect, blinds the insect so that biting and feeding is not triggered.
It is available in a variety of liquids, lotions, sprays, and impregnated materials (e.g., wrist bands) in formulations ranging between 4 to 100% DEET. Research has shown a direct correlation between DEET concentration and hours of protection (leveling off at 50% strength). Full 100% DEET may work up to 12 hours while 20-34% DEET may only work up to 3-6 hours.
DEET use has not show any significant harmful effects on humans, but studies on rats and reports of military use show decreased performance with physical tasks requiring muscle control, strength and coordination with use of DEET.
DEET is also and effective solvent and can damage some plastics (eyeglass frames), watch crystals, rayon, spandex, other synthetic fabrics and leather. It does not damage cotton, wool or nylon.
Brands: There are about 230 brands, formulations and concentrations of DEET available. Many major drug store chains also carry their own labels.
Controlled release formulations include:
3M Ultrathon (polymer-based)
Sawyer Controlled Release (microencapsulated)
Picaridin (1-piperidinecarboxylic acid 2-(2-hydroxyethyl)-1methylpropylester, Icaridin, KBR 3023, and Bayrepel)
Picaridin is an almost colorless and odorless liquid used as an insect repellant against biting flies, mosquitoes, chiggers, and ticks. It works by blocking specific olfactory receptors of the insects, making it difficult for and insect locate its host.
Picaridin is available in sprays and wipes with formulations ranging between 5 to 20% of the active ingredient.
It is reported to have comparable effectiveness as DEET without the skin irritation common with DEET. It is one of the three repellants recommended by the CDC and is recommended by the WHO for protection against malaria. Other studies suggest that Picaridin has much lower efficacy than DEET or Oil of Lemon Eucalyptus.
Compared to DEET, Picaridin does not have adverse effects on plastics, synthetics, plastic coatings or sealants. It also needs to be reapplied more frequently than DEET and may not be effective against ticks.
MGK-326 (Di-n-propyl isocinchomeronate)
This is a repellent used with DEET and MKG-264 to repel biting flies. I was classified as a probable human carcinogen and therefore, total concentration is limited to 2.5% by the EPA with a maximum of 3 application per day.
It is marketed with DEET to repel horse flies, deer flies, stable flies, black flies, no-see-ums, gnats, mosquitoes, fleas, chigger and ticks.
Cutter Tick Defense
MGK-264 (n-Octyl bicycloheptene dicarboximide)
A mosquito repellent and synergist used with DEET and MGK-326.
Cutter Tick Defense
Animal Flea and Tick Collars
These are made for animals and should not be used on humans. If worn, your sweat can leach out dangerous amounts of chemicals from the collars themselves and cause significant burns or systems poisoning. This can even happen if the collar is worn outside a layer of clothing or even some footwear. There are safer and more effective options available to most trekkers and this technique/practice is not advised.
Animal collars may contain pesticides such as insect growth regulators (methoprene), organophosphates (tetrachlorvinphos), carbamates (carbaryl, propoxur), and formamidines (Amitraz).
Many backpacker prefer to avoid man made pesticides and choose instead to go with more natural or herbal bug treatments. With the exception of Oil of Lemon Eucalyptus, most of these demonstrate poor bug repellency and need to be reapplied more frequently.
Oil of Lemon Eucalyptus is a natural oil found in eucalyptus leaves and twigs. As with many other natural oils, no adverse effects to humans are expected. It has a distinct odor that seems to drive marmots a bit crazy.
It is available in both lotion and spray insect repellents in formulations ranging from 30 to 40% of the active ingredient. Several studies show efficacy against mosquitoes almost as good as DEET, making it a good "natural" alternative to DEET.
Repel Lemon Eucalyptus Insect Repellent
p-Menthane-3,8-diol is the chemically synthesized version of oil of lemon eucalyptus. It is applied to skin or to clothing to repel specific insects including mosquitoes, biting flies, and gnats. It is available in formulations ranging from 8 to 10% of the active ingredient.
Methyl nonyl ketone (CH3CO(CH2)8CH3, 2-Undecanone, IBI-246)
Methyl nonyl ketone is manufactured synthetically but can be extracted from oil of rue and is found naturally in bananas, cloves, ginger, guava, and strawberries. It was originally registered as a dog and cat repellent/training aid and an iris borer deterrent. Methyl nonyl ketone is currently found in only one US registered insect repellent in the form of both a lotion and a spray. Studies for at least the Senzazzz repellent don't seem to support effectiveness as an insect repellent but there is a lot of hype about the new US SkeeterShield.
IR3535 (chemical name, 3-[N-Butyl-N-acetyl]-aminopropionic acid, ethyl ester, Merck 3535)
IR3535 is used as an insect repellent against mosquitoes, deer ticks, and biting flies. This biopesticide has been used as an insect repellent in Europe for 20 years with no significant harmful effects. Products are formulated as sprays, in sun block, towelettes, and lotion and range between of 7.5 to 20.07% of the active ingredient.
IR3535 has been shown to have less mean protection (0-3 hour only) against mosquitoes than other repellents. For blacklegged ticks, it seems to be as effective as DEET with double the concentration of IR3535 for up to 3 hours.
Skin-So-Soft Bug Guard Plus Insect Repellent
Oil of Citronella comes from dried, cultivated grasses (Cymbopogon nardus), and has a distinctive odor that masks the CO2 or lactic acid on our bodies that mosquitoes and other pests find attractive. It has been used for over 50 years as an insect repellent. However, oil of citronella is included on the list of chemicals that may not require EPA registration in some cases. Unless a product containing citronella is EPA-registered, it has not been subject to EPA review and EPA cannot corroborate its safety and effectiveness. Oil of citronella products are commonly sold as repellent candles but only skin applied products offer some protection in certain circumstances. Most skin-applied products contain about 5 percent oil of citronella.
Natrpel (Oil citronella only)
Green Ban for People (Oil citronella, peppermeint, others)
Buzz Away (Oil of citronella, peppermint, others)
Herbal Armor (microencapsulated oil citronella, peppermint, others)
Soybean oil is one of the many herbal insect repellents on the market. It is generally mixed with other herbals and is generally safe to use. Unfortunately, many applications containing soybean oil don't seem to offer much protection against biting insects and must be reapplied frequently. Bite blocker has been shown to be effective against Cx. nigripalpus and offers a reasonable duration of protection against other mosquito species.
Bit Blocker Herbal Repellent
Repellents Used on Clothing
There are several products used to treat mosquito nets, tents and clothing. They provide longer term treatment and may last months to years depending on application. When added to netting, they provide a good combination of chemical and physical protection from biting bugs.
Several companies manufacture pretreated clothing, netting and even insecticide incorporated plastic sheeting (ZeroFly deltamethrin, Vestergaard) for shelter construction.
Permethrin is registered for use as both an insecticide and a repellent. It is now synthetically manufactured pyrethroid but was once derived from dried flowers of the daisy Chrysanthemum cinerariifolium. It works as an contact insecticide by causing nervous system toxicity that leads to the death or "knockdown" (out of the air) of the bugs.
This product is usually used to treat clothing, shoes, mosquito nets, tents and other camping gear. Permethrin is also found in treated tents, tarps, bed nets, sleeping bags, and mattresses. Once treated, the permethrin-impregnated clothing/gear works by killing ticks but also has some repellent capabilities. It is also said to be effective against against mosquitoes, flies, and chiggers and retains this effect for at lest 2 weeks, even after repeated laundering.
Coulston's Duranon Tick Repellent
Sawyer Clothing Tick Repellent
Cutter Outdoorsman Gear Guard
3M Clothing and Gear Insect Repellent
No Stinkin Ticks
Deltamethrin is a synthetic pyrethroids and is relatively safe for human use when applied to netting. This is used to treat mosquito netting and for elimination of spiders, fleas, ticks, carpenter ants, carpenter bees and cockroaches.
Deltamethrin is a neurotoxin and should never be ingested, inhaled or used on you skin.
There are may coils, sprays and other area repellents. The can be used to treat tents, rooms and outdoor areas with limited protection against bugs.
Allethrin (C19H26O3, Alleviate, Pynamin, d-allethrin, d-cisallethrin, Bioallethrin, Esbiothrin, Pyresin, Pyrexcel, Pyrocide and trans-allethrin)
Allethrin is synthetic compound that duplicates the activity of the pyrethrin plant and origionally was extracted from chrysanthemum flowers. It works on the stomach and respiratory system of insects and paralyzes insects before killing them. Not used as a topical agent, it used as an outdoor area-wide repellent that is used for the control of mosquitoes. Heating causes allethrin to vaporize from mosquito coils, mats, and oil formulations. It is also used frequently in commercially available aerosol spray and tabletop candles and lanterns.
Ace Wasp & Hornet Killer2 (with tetramethrin)
Ace Flea & Tick Killer for Pet and Home
Green Thumb Wasp & Hornet Killer (with tetramethrin)
Hot Shot Wasp & Hornet (with tralomethrin)
Hot Shot Flying Insect Killer (with permethrin)
OFF! Mosquito Coil
Ortho Home Defense Flying Insect (with phenothrin)
Raid House and Garden
Raid Yard Guard (with permethrin)
Summit Outdoor Mosquito Repellent Coils
Metofluthrin is a vapor-active pyrethroid that is highly effective against mosquitoes. It is impregnated in paper sheets or plastic grids called emulators and are designed to be hang up as an area repellent. No heating is necessary to vaporize the metofluthrin after the strips are removed from the packaging. Metofluthrin is also used in several mosquito coil products.
Bifenthrin is a pyrethroid insecticide that affects the nervous system of insects. The EPA has classified bifenthrin as a class C carcinogen (possible human carcinogen).
Ortho Home Defense Max
Burning ordinary candles has been show to potentially reduce the number of mosquito bites 23%. This reduction in mosquito bites is possibly due to the burning candle causing a decoy source of warmth, moisture, and carbon dioxide.
Under test conditions, burning citronella candles have shown a 42% reduction in mosquito bites in persons near the burning candle. Other studies have shown that burning wood and leaves can reduce mosquitoes bites by over 50%. Candle, wood and other smoke of course has its own health risks, especially if used frequently and/or in a poorly ventilated building.
Mosquito Coils are very popular in Asia. They are made from a paste of powdered insecticide and a filler such as sawdust. The paste is then extruded into a spiral shape. This spiral coil is mounted on a metal stand so that the free end can be lit like an incense stick. The smoldering coil burns at a steady rate for 6 to 8 h, releasing smoke and insecticide. The insecticide then works as a fumigant to kill resting mosquitoes that may feed overnight.
Coils vary greatly in composition, strength and quality. The active ingredients may contain metofluthrin (considered very potent), allethrin, other pyrethroids, DDT (generally considered to be less effective) or even lindane. Effectiveness and potential health hazards of the coils depend in part on the insecticide used in the coil as well as its concentration. Research has shown that coil smoke contains carcinogens, suspected carcinogens and formaldehyde. Of note, the amount of fine and ultra fine partials in coil smoke can be equivalent to burning 75-137 cigarettes.
Overall, most studies on mosquito coils have shown an overall reduction in bites with various levels of bite inhibition, repellency, knockdown, deterrence and mortality. Travelers should be cautious of potentially hazardous insecticides that may used in coils purchased abroad and the cancer potential of coil smoke inhalation. Sleep tight.
.DDT is still used in many parts of the world as an area pesticide and is used as the main ingredient in some mosquito coils. It is unfortunately quite toxic, causing detrimental effects on the environment and is know to be a cancer causing agent. Because of its severe toxicity, it was banned world wide back in the 1980s. But despite the health and environmental drawbacks of DDT use, the WHO feels that the DDT's potential for combating malaria and other bugborne diseases far outweighs these drawbacks. It can still be found in use in many African and Asian countries.
Be aware of DDT use, its potential benefits in combating malaria (supported by the WHO) and its cancer causing potential. Use with caution.
When stationary, nothing protects you from bugs like a properly constructed and or treated mosquito nets that has been set up properly. Because of this, there are many net products available for trekkers worldwide. Unfortunately not all netting used to protect against bugs are effective.
The most important feature of netting effectiveness is hole size. If the smallest hole sizes on a net are larger than the bug you would like to keep out, it isn't going to be very effective unless it is also treated with a long lasting insecticide. Netting with smaller holes will prevent smaller bugs from passing through through the net, but will decrease airflow through the net. Netting with larger holes will allow smaller bugs to pass through the netting, but will also allow for more airflow.
A netting with homogenous hole of less than 2mm in diameter is recommended for protection against most malaria carrying mosquitoes. The WHO seems to feel that netting with 156 hole count (156 holes per inch) is sufficient to protect against most malaria carrying mosquitoes and 196 hole count (196 holes per inch) is sufficient to protect against sand flies. Others recommend a hole count of 200 holes per inch2 (31 holes per cm2) for protection against mosquitoes and 600 holes per inch2 (93 holes per cm2) for No-See-Um size.
Material needs to be durable enough that it doesn't tear easily. Since backpackers are be packing and unpacking their net repeatedly and possibly setting it up in the bush with multiple fabric hazards (branches, jagged rocks, feet of tiered trekkers), they may need a more durable net that those made for home use.
Netting is often made with polyamide (nylon), polyester (Terylene) or cotton. Nylon is the strongest material (by weight), while polyester has better UV protection. Cotton is not ideal for backpack use, since it is a relatively weak material compared to nylon or polyester, it absorbs moister and tends to rot. Monofilament (fishing line appearing material) nets are also a poor choice since the threads can easily separate and create holes large enough for mosquitoes and other bugs to pass.
Material used is also an important factor when chemically treating a bug net. Cotton absorbs a lot more chemical than polyester and will require more chemical to treat similar surface areas of polyester. Therefore, polyester netting made from fibers with a filament count greater than 30 is recommended for field level insecticide treatment by the WHO.
Polyester seems to make the best netting for backpacking use.
A mosquito net needs to cover the user without having any openings that would allow bugs to pass. There generally needs to be enough extra material to lay on the ground or be tucked in under bedding so that bugs don't just pass underneath the net.
The available space under a net will effect temperature and generally comfort. The more space you have the cooler you should be. The design and size of a net will also determine if you can sit or stand up or how much you can move around. Rectangular nets may be more difficult to set up but may provide more comfortable usable space than canopies that hang down from a single point.
Several manufactures make long-lasting insecticidal nets (LLINs). These nets are treated with long lasting insecticide and offer greater protection to those within the net and even some protection to those around the net but not covered by it. The WHO recommends retreating after 3 washes or at least once per year.
The WHO feels that netting treated with long-lasting insecticides can get away with larger holes and recommend a minimum hole size of 56 holes per inch2. This allows for better air flow and cooler temperatures under the net.
Netting is manufactured in many parts of the world and quality varies greatly. The netting material itself or stitching can come apart and allow all kinds of bugs entry. If you find that your net is falling apart, you can try to sew or use duct tape for temporary fixes until you can find a better replacement.
For those new to the bug world - a mosquito net must to setup so that the netting is not touching or will potentially touching (after you roll over at night) any part of your body and that all loose ends are either tucked in under bedding or secured to the ground with gear, rock, etc. Proper netting will stop entry of bugs but won't stop them from biting skin touching the net.
Some novice travelers have been know to wrap themselves up in nets at night to find hundreds of bites on them in the morning. Take the time to set up a net properly before going to sleep and if you have never set up a net before, you might want to ask someone to show you how.
Besides a net, you will likely need string, duct tape (for walls), very basic knot tying knowledge, and something to attach the string to (tree, vehicle, etc). Rocks and sticks may also be needed to keep the bottom of the net on the ground.
What Works in Combating Bugs
There are a lot of different insect and bug treatment options available for backpackers, but not all products are effective.
Avoiding Bug Infected Areas
If you don't visit or sleep in areas or countries known to have biting insects, you are less likely to get bit. Avoid swamps (mosquitoes), dense woods, fields, and brush (ticks, chiggers).
Topical Bug Spray
Against most biting bugs, controlled release DEET works well and last for many hours. It is the gold standard for bite bug repellents and is supported by a great deal of research. The higher the concentration (up to 50%), the long it is expected to provide protection.
Oil of Lemon Eucalyptus works well but needs to be reapplied more often than DEET. It is preferred by many since it is a little easier on the skin and is thought to be "natural" (despite it often being a synthesized copy of the natural oil). Most other topical insect repellents are more or less ineffective or require frequent reapplications.
The following two comparison studies suggest that DEET at higher concentrations provide the best protection against mosquitoes while Repel lemon eucalyptus and Bite Blocker provide reasonable protection but for decreased durations. It is important to note that test conditions (wind, species, exposure intervals, positive bite guidelines, etc) differ greatly between these two studies, so the duration of repellency results should only be compared to results within the same test.
In 2002, Fradin and Day did a comparison of 13 commercial topical bug repellents against Aedes aegypti mosquitoes and found the following:
Average Hours of Repellency Product
OFF! Deep Woods (23.8% DEET) 3.9 Sawyer Controlled Release (20% DEET) 1.9 OFF! Skintastic (6.65% DEET) 1.6 Bite Blocker for Kids (2% Soybean oil) 1.5 OFF! Skintastic for Kids (4.75% DEET) 0.4 Skin-So-Soft Bug Guard Plus (7.5% IR3535) 0.3 Natrapel (10% Citronella) 0.3 Herbal Armor (12% Citronella, 2.5% peppermint oil, cedar oil, 2%, 1% lemongrass oil, 0.05% geranium oil) 0.2 Green Ban for People (10% Citronella, 2% peppermint oil) 0.2 Buzz Away (5% Citronella) 0.2 Skin-So-Soft Bug Guard (0.1% Citronella) 0.2 Skin-So-Soft Bath Oil (Uncertain) 0.0 Skin-So-Soft Moisturizing Suncare (0.05% Citronella)
In 2004, Barnard and Xue did a comparison of 12 commercial bug repellent against Aedes albopictus, Culex nigripalpus, and Ochlerotatus triseriatus mosquito species and found the following:
Average Hours of Repellency Product 7.6 Repel (26% p-menthane-3,8-diol aka oil of lemon eucalyptus) 7.2 Bite Blocker (2% soybean oil, glycerin, lecithin, vanillin, oils of coconut and geranium) 7.2 Autan (10% picaridin) 7.2 Off! (15% DEET) 4.8 Skinsations (7% DEET) 3.2 IR3535 (7.5% aka Skin-So-Soft) 3.1 MosquitoSafe (25% geraniol) 2.3 Natrapel (10% citronella) 1.5 Neem Aura (Aloe vera, extract of barberry, camomile, goldenseal, myrrh, neem, and thyme; oil of anise, cedarwood, citronella, coconut, lavender, lemongrass, neem, orange and rhodiumwood) 1.5 SunSwat (oils of bay, cedarwood, citronella, goldenseal, juniper, lavender, lemon peel, patchouli, pennyroyal, tansy, tea tree, and vetivert) 1.5 Bygone (oils of canola, eucalyptus, peppermint, rosemary, and sweet birch) 0.9 GonE (Aloe vera, camphor, menthol, oils of eucalyptus, lavender, rosemary, sage, and soybean)
Nothing works better for bug protection than a properly setup and designed mosquito net. The going standard for mosquito protection is 200 holes per inch2 and 600 holes per inch2 for No-See-Um size pests. Many mosquitoes are able to squeeze through many of the commercial nets available and it is recommended that you use a good quality No-See-Um size net to adequately protect against mosquitoes and other bugs.
Mosquitoes and other bugs may be able to bit through thin clothing, but use of long sleeved shirts, pants, cover footwear, etc will decrease the amount of bug bite you would get compared to having more exposed skin. Pant can be tucked into socks or boots and shirt should be tucked into pants for added protection.
Some clothing will come pretreated with repellents and may offer a bit extra protection.
Treating bug nets is ideal and many environments will deem the need for treatment of clothing. Both permethrin and deltamethrin are good options.
Buggy rooms or campsites can be treated with several products. Metofluthrin has been shown to work quite well and there are several coil and spray products that may be of some benefit. Many of the sprays available may be hazardous to your health, but give you the satisfaction of killing bugs in front of your eyes.
DDT is still used in many parts of the world and in some mosquito coils. Although this is one of the best pesticides around, it raised enough health and environmental concerns in the US and Europe to warrant banning. Be aware of DDT use, its potential benefits in combating malaria (supported by the WHO) and its cancer causing potential. Use with caution.
Things that Don't Work
There are many products on the market and techniques that have not been show to be beneficial in repelling biting arthropods. These include:
Ingested compounds including garlic and thiamine (vitamin B1)
Small wearable devices that emit sounds that are purported to be abhorrent to biting mosquitoes
Wristbands impregnated with DEET or citronella
Bug zappers destroy beneficial bugs and has almost no effect on female mosquitoes
Setting up bird or bat houses nearby
Treatment of Bites and Infestations
Treatment for most bites
Although this may be difficult to impossible, you should avoid scratching bites, as this damages skin and can lead to bacterial infections.
Topical corticosteroids (hydrocortisone) help with redness, itching and swelling.
Avoid topical diphenhydramine (Benadryl) and caine-containing anesthetics (benzocaine, butamben, dibucaine, lidocaine, oxybuprocaine, pramoxine, proparacaine, Alcaine, proxymetacaine, tetracaine, amethocaine) since there are concerns about inducing allergic contact sensitivity.
Oral antihistamines (diphenhydramine, Benadryl) can reduce itching, redness and swelling.
Cetirizine and nonsedating antihistamines given prophylactically may help with itching and other symptoms in travelers who have had previous severe reactions to mosquito bites.
Scabies and Lice Treatment
Scabies and lice don't just bite, they either attach themselves to hair (lice) or burrow under skin (scabies) and stick around for the long haul. To get rid of scabies or lice, you will need a good washing, to include laundering and heat drying of all you clothing and bedding and you will most likely need help from topical or even oral medications.
Topical medications such as Lindane (Kwell), Permethrin 1% (Nix), permethrin 5% (Elimite), Pyrethrins Plus Piperonyl Butoxide (Rid), sulfur 4% in Vaseline base or Malathion 0.5% lotion (Ovide) may be needed to clear them from your body and hair. Topical treatment may need to be repeated and each of these medications have their on boxed warnings.
Dose Application 0-1 year 1-4 years 5-11 years 12+ years Frequency Leave on Lindane 1% Not recommended Not recommended Not recommended 200mls Once 12-24 hours Permethrin 5% 4g 8g 15g 30-60g Once 8-24 hours Benzyl Benzoate Not recommended Not recommended Often irritant 200mls Twice 24 hours Sulphur 4% 8g 12g 24g 50g Three times 48 hours Malathion 20mls 40mls 100mls 200mls Once 24 hours
More resistant lice may need oral medications such as Trimethoprim-sulfamethoxazole (Septra, Bactrim) or a one time dose of Ivermectin (Stromectol).
For lice, if medications are not available, there are several alternatives treatments that may be effective.
Combing (fine steel comb preferred) to remove eggs and critters
Coat hair and skin with Vaseline, petroleum jelly, full fat mayonnaise or vegetable oil to suffocate lice - work through scalp, cover with shower cap overnight, rinse and then comb out nits.
Use a hair drier to kill bugs and eggs with heat
Sulfur creams can be made at home with Vaseline, lard or other ointments
When a honey bee stings, it leave behind a stinger that will likely have some residual venom in it. Trying to grab a stinger of the surface of skin with tweezers may squeeze the contents of the stinger and inject more venom into the sting victim.
You can removed the stinger by sliding a razor along the skin to push the stinger out without squeezing it.
If a tick has already attached itself to you, you should use a pair of thin-tipped tweezers to grip the tick firmly under the head end and push down to disengage the "teeth" then gently pull away. Once removed, the bite area should be treated with an antiseptic.
There are several spiders that are poisonous and can cause different types of problems with trekkers. Some have neurotoxins that can be deadly, while other can cause a great deal of tissue damage requiring hospitalization and professional medical treatment. Spider bites should be treated as snake bites and medical help sought if symptoms occur.
Bot Fly Maggots
Bot fly maggots live in a host's skin for about 6 weeks and need air from outside the host to breathe. Use Vaseline, chewing gum, bees wax, heavy oil, fingernail polish, adhesive tape, heavy makeup cream or other occlusive cream to cover the skin to block air from reaching the maggots. This will either suffocate them or force them to come up for air. If they surface, get them with your tweezers and try to pull them out whole.
Pork fat is used natives to occlude the breathing hole and draw the larva out into it. The drawback of this technique is that - should it fail, you may have a dead larva and pork fat trapped under your skin.
Locals also sometime use two wooden spoons, one of each side of the nodule to simultaneously squeeze the larva and force it out of the breathing hole intact.
Another technique involves injecting the breathing hole with lidocaine and removing the entire larva through the hole.
Unfortunately, the most common techniques involves incising the skin and removing larva. This has the potential problem of leaving cut larva parts behind and can be a big project requiring you to cut up a lot of skin if you need to treat a large number of larva nodules.
Bot Fly infestations are often misdiagnosed or outright dismissed by Western medical providers and after reading this page, you are likely to know more about Bot Fly infestation treatment than most doctors in the US and Europe. It is therefore important to seek out a provider familiar with tropical medicine experience/training if you feel you may potentially have Bot Fly larva under your skin and to let them know about recent travels and the concern about Bot Flies specifically.
References and additional information
Centers for Disease Control and Prevention (CDC)
U.S. Environmental Protection Agency (EPA)
World Health Organization (WHO)
Fradin MS. Mosquitoes and mosquito repellents: a clinician's guide. Ann Intern Med. 1998 Jun 1;128(11):931-40. Link
Barnard DR, Xue RD. Laboratory evaluation of mosquito repellents against Aedes albopictus, Culex nigripalpus, and Ochierotatus triseriatus (Diptera: Culicidae). J Med Entomol. 2004 Jul;41(4):726-30. Link
Frances SP, Waterson DG, Beebe NW, Cooper RD. Field evaluation of commercial repellent formulations against mosquitoes (Diptera: Culicidae) in Northern Territory, Australia. J Am Mosq Control Assoc. 2005 Dec;21(4):480-2.
Fradin MS, Day JF. Comparative efficacy of insect repellents against mosquito bites. N Engl J Med. 2002 Jul 4;347(1):13-8. Link
Xue RD et al. Laboratory evaluation of toxicity of 16 insect repellents in aerosol sprays to adult mosquitoes. J Am Mosq Control Assoc. 19.3 (2003):271-4.
Lawrance, C. E., and Croft, A. M., Do mosquito coils prevent malaria? A systematic review of trials., J Travel Med, 11, 92 2004.
Ujihara K, Mori T, Iwasaki T, Sugano M, Shono Y, Matsuo N. Metofluthrin: a potent new synthetic pyrethroid with high vapor activity against mosquitoes. Biosci Biotechnol Biochem. 2004 Jan;68(1):170-4.
Liu W, Zhang J, Hashim JH, Jalaludin J, Hashim Z, Goldstein BD. Mosquito coil emissions and health implications. Environ Health Perspect. 2003 Sep;111(12):1454-60.
Hensel P. The challenge of choosing a pediculicide. Public Health Nurs. 2000 Jul-Aug;17(4):300-4.
Czachor JS, Elder BL, Sutherin SR. Travelers Beware the Bot Fly! J Travel Med. 1995 Dec 1;2(4):264-266.
Masetti A., Maini S. Arm in cage tests to compare skin repellents against bites of Aedes albopictus. Bulletin of Insectology 59 (2): 157-160, 2006.
Please feel free to link to this site so that others can find it. It's easy to link to this site - simply copy the text below onto your web page.
Copyright © 2000-2005