Bugs and Bites
Living in a natural environment exposes us to insects and parasites such as mosquitoes and ticks. These creatures can sometimes be the carriers of diseases which you will want to avoid. We can live in this environment more comfortably by being prepared. Learn about these creatures and the best way to protect yourself from them. — As they say, “Prevention is better than cure”.
One of the most reliable ways to minimise the risk of exposure to pest arthropods is to avoid their natural habitats (e.g. known mosquito or tick habitats) or limit their ability to infest a house or workplace (e.g. bed bugs or bird mites). This relies on knowledge of the pest, their natural habitats and environmental triggers for activity or population increases. For many pests, these factors may change depending on their geographic distribution across Australia.
Insect repellents are usually applied to the skin to stop biting insects identifying the person as a potential blood meal. Repellents are often used against biting midges, mosquitoes and ticks, although they can sometimes be used against other blood-feeding arthropods (e.g. bed bugs, bird mites). Although the specific mode of action for many repellents is not fully understood, they usually stop the arthropod from biting by either blocking the cues that identify the host as a potential blood meal or providing an odour that overrides that of the host. There is a wide range of repellents available, classified as either synthetic or botanical in nature.
This term generally applies to chemically produced or synthesised repellents. The most effective and widely used repellent internationally is DEET (diethyltoluamide). Developed by the United States Army in the 1950s, DEET is now used by many millions of people around the world and is available in a wide range of application formulations (e.g. roll-ons, lotions, aerosols, pump-sprays and wipes) and concentrations. Generally, repellents containing less than 10% DEET will offer up to two hours’ protection from biting arthropods and are suitable for general use. Repellents that contain up to 80% DEET are more suitable for long periods of exposure to biting arthropods in areas of endemic vector-borne disease.
Picaridin is another widely available active ingredient found in commercial insect repellents in Australia. This product was developed more recently, is generally thought to have a more pleasant scent than DEET and has lower toxicity to humans (making it more appropriate for use on children). Scientific studies have shown that this product is equally effective at preventing insect bites as DEET.
There are a large number of plants whose essential oils or extracts may provide protection against biting insects. The most common products come from strongly aromatic plants, such as eucalypts or tea-tree, and commercial products often contain a blend of extracts. Many scientific studies have compared botanical and synthetic repellents and, although botanical products may provide some protection, products such as DEET and picaridin provide substantially greater and longer term protection, even at low concentrations. Some natural products offer protection for only a few minutes, leaving users unprotected and exposed to disease-carrying vectors. However, research on repellents with botanical-based active ingredients is continuing and these products may be useful under some circumstances.
Coils, sticks and other gadgets
Burning plant material to repel biting insects has been used by many cultures for thousands of years. Today, the tradition continues in the form of mosquito coils and sticks. The mosquito coil is the most popular form of personal protection from biting insects over the past 100 years. These devices are made of materials impregnated with insecticide (e.g. synthetic pyrethroids, such as allethrin) that burn slowly (some coils burn for up to eight hours) and may provide up to 80% protection. Some formulations are also available with botanical active ingredients, but these are generally less effective. Coils are cheap to produce and easy to operate, although the smoke produced may present a health risk when used indoors. There is also a number of electronic units available (for both indoor and outdoor use) that release insecticides from slow-release mats or liquids. These units can be very effective, as the pyrethroids kill mosquitoes rather than simply repelling them.
A wide range of products claim to repel biting insects in formulations other than topical repellents. Products containing synthetic or botanical active ingredients can include patches and wrist bands that claim to provide a degree of protection. However, scientific studies have shown that these products offer substantially less protection than topical repellents.
All repellents used in Australia, whether synthetic or botanical, must by law be registered with the APVMA and the approval number must be listed on the label.
There is often a perception that synthetic repellents, such as DEET, are unsafe. However, despite the widespread use of DEET-based products internationally, there are very few cases of adverse reactions. Most of these cases involve serious misuse, most commonly applying too much of the product (especially on young children), eating it or exposing the eyes to the product. Botanical-based products can also cause irritation. The risk of an adverse reaction from using a repellent is very low and failing to use repellents in some locations will almost certainly result in insect bites and the real possibility of acquiring an infectious disease.
Regardless of the active ingredient, all repellents should be applied according to the instructions on the label.
All insecticides must be registered with the APVMA for use in Australia. Detailed discussion of the most suitable products for controlling specific pests is beyond the scope of this document and professional pest managers may be needed to treat serious infestations. However, in many cases, household insecticides (either knockdown aerosols or long-lasting residual surface sprays) may be a cost-effective solution to lessen the short-term effects of some biting arthropods. The one notable exception to this is for bed bugs, as household products are generally ineffective and can cause the infestation to spread, making eradication more difficult and expensive.
Physical and chemical barriers against pests are often very effective. Screened windows, doorways and balconies, and bed nets provide protection from flying insects, and insecticide applications to the building or surrounding vegetation may provide further protection. Some vertebrate animals, such as bandicoots, rodents and birds can carry arthropod pests; barriers that stop these animals from entering properties are often the best way to minimise the risks of exposure to these arthropods.
Many electronic (e.g. ultrasonic) devices are available that claim to repel invertebrate and vertebrate pests, but these have repeatedly been shown to be ineffective. These devices continue to be adapted to new technologies with options available for mobile phones, portable music players and other digital devices but, unfortunately, no new advances in their actual repellent properties have been made.
Traps and lures
A wide variety of traps and lures are designed to control arthropod pests. These traps and lures vary greatly, not only in their design and mode of action (e.g. electrocuting lights, carbon dioxide-baited suction traps, sticky paper, shelter providers), but also in their effectiveness in controlling pests. Although many of these devices collect pest arthropods, few offer complete protection from pest effects, long-term population control or eradication. However, they may be an important component of integrated pest management strategies and can be a useful tool in monitoring pest populations.
One of the most effective tools to assist personal protection is knowledge. Information about locally important pests and their biology, ecology and potential health impacts will allow the individual to better avoid exposure to the pests’ bites, stings and disease-causing microorganisms. It is hoped that this document will go some way towards improving the availability of knowledge on many of Australia’s most important arthropod pests.
Ross River fever fact sheet
Ross River fever is caused by a viral infection, transmitted through mosquito bites. Symptoms include fever, rash, and joint pains. Prevention relies on avoiding mosquito bites.
Last updated: 01 May 2016
What is Ross River fever?
Ross River fever is caused by infection with Ross River virus, one of a group of viruses called arboviruses (or arthropod-borne viruses), which are spread by the bite of infected mosquitoes.
What are the symptoms?
Many people who are infected with the virus will never develop symptoms.
- Some people will have flu-like symptoms that include fever, chills, headache and aches and pains in the muscles and joints.
- Some joints can become swollen, and joint stiffness may be particularly noticeable in the morning.
- Sometimes a rash occurs on the body, arms or legs. The rash usually disappears after 7 to 10 days.
- A general feeling of being unwell, tired or weak may also occur at times during the illness.
- Symptoms usually develop about 7-10 days after being bitten by an infected mosquito.
- The majority of people recover completely in a few weeks. Others may experience symptoms such as joint pain and tiredness for many months.
How is the virus spread?
The virus is spread by certain types of female mosquitoes.
- Female mosquitoes feed on animals and people. If they feed on the blood of an infected animal, the mosquito may become infected. The virus then multiplies within the mosquito and is passed to other animals or people when the mosquito feeds again.
- The number of infections tends to peak in the summer and autumn months.
- The virus is not spread directly from one person to another.
Who is at risk?
People who are in contact with known mosquito habitats and who live in warm, humid climates near bodies of water will be most at risk of infection. Ross River virus infections are the most common mosquito-borne infection in Australia, and infections occurs in many rural areas in NSW. Infections are uncommon in major cities and towns. Outbreaks can occur when local conditions of rainfall, tides and temperature promote mosquito breeding.
How is it prevented?
There is currently no vaccine against Ross River virus.
To protect against mosquitoes and reduce the risk of diseases they transmit:
- cover-up with a loose-fitting long sleeved shirt and long pants when outside
- apply mosquito repellent to exposed skin
- take special care during peak mosquito biting hours, especially around dawn and dusk
- remove potential mosquito breeding sites from around the home and screen windows and doors
- take extra precautions when travelling or camping in areas with a higher risk of mosquito-borne diseases.
For more detailed information on reducing the risk of mosquito bites at home and while travelling see the Mosquitoes are a Health Hazard factsheet. This also includes more information on mosquito repellents
How is it diagnosed?
Ross River virus infection is diagnosed by detection of antibodies against the virus in the blood. It usually requires comparison of a blood test taken early in the illness and with another sample taken two weeks later to confirm the infection.
How is it treated?
There is no specific treatment for Ross River virus infection. Your doctor will be able to advise you on medications that will help ease the discomfort of the symptoms.
What is the public health response?
Laboratories are required to notify cases of Ross River, and other mosquito-borne disease to the public health unit. Public health staff monitor the geographic spread of Ross River virus infections and provide information about avoiding mosquito-borne diseases.
- Mosquitoes are a Health Hazard fact sheet
- For more information, please call your local public health unit on 1300 066 055.
An article from Sydney University providing useful information on how to best manage them.
The following article was complied with information from the Department of Medical Entomology, University of Sydney and Westmead Hospital.
There are over 300 species of mosquito in Australia but less than 20 represent a risk to humans, either as nuisance-biting pests or carriers of disease.
When mosquito populations are high, biting may be experienced at any time of the day but, generally, mosquitoes are most active at dawn and dusk. In Far North Queensland the dengue mosquito will bite throughout the day.
During the warmer months, mosquitoes can take less than one week to complete their development from eggs to adults. Adult mosquitoes typically live for up to 3 weeks. Blood feeding on humans or animals provides the protein required for egg development, therefore only female mosquitoes bite. Mosquitoes are primarily attracted to carbon dioxide and the “smell” of our skin. Each mosquito species varies in its propensity to bite humans. People can vary in both their attractiveness to mosquitoes and their sensitivity to a mosquito bite. Mosquitoes rarely emerge infected with a virus, they must acquire it from feeding on an infective animal and the virus must infect the mosquito (a complex process that may take up to 10 days) before the virus can be transmitted to a human.
Mosquito myths and misconceptions
There is no scientific evidence that eating or drinking any particular food e.g. bananas or garlic can reduce the likelihood of being bitten by mosquitoes. There is no scientific evidence that taking vitamin B will reduce the likelihood of, or lessen the severity of an individual’s reaction to, a mosquito bite. Mosquitoes cannot transmit HIV or any disease other than specific mosquito-borne viruses. Blood type and skin colour are generally not good predictors of the likelihood of being bitten. Any activity (e.g. exercise) that increases body temperature or causes sweating may increase the risk of being bitten by mosquitoes. Studies show that pregnant women may be more likely to be bitten by mosquitoes due to increased body temperature. Studies have shown that the consumption of alcohol may increase the risk of being bitten by a mosquito due to increased body temperature.
As well as the use of repellents, wearing loosely fitting long pants and long sleeved shirts will assist in reducing the number of mosquito bites received. Clothing can also be pre-treated with insecticides (e.g. permethrin) for added protection.
Insect repellents assist in preventing bites by repelling mosquitoes or inhibiting the mosquito’s stimuli for blood feeding. The stronger the concentration of an insect repellent, the less frequently it will need to be applied to stop mosquito bites Repellents containing low concentrations of DEET or Picaridin, if applied correctly, should stop mosquito bites for around two hours The formulation (e.g. roll-on, spray or lotion) doesn’t influence the product’s effectiveness as long as the repellent itself is evenly applied to the skin”
All insect repellents should be registered with the Australian Pesticides and Veterinary Medicines Authority (APVMA) before being made available for sale. Over 60 individual repellent formulations are currently registered. Brand names may vary but there are three main categories of repellents available; synthetic chemicals (DEET, picaridin and PMD), botanically derived products (e.g. Eucalyptus, Citronella, Melaleuca) and “wearable” devices. Wearable patches and wrist bands, typically impregnated with botanical products, do not offer effective protection from mosquitoes.
DEET (diethyltoluamide) was developed by the US Army in the 1950s and is the most widely used and effective repellent. In Australia, it is available in formulations ranging from than 10% up to 80%.
Picaridin (also known as Icaridin) was developed in the 1990s and while proven to be as effective as DEET, is generally thought to have a more pleasant scent. In Australia, it is available in formulations ranging from 10% to 20%.
PMD (registered in Australia as “extract of lemon eucalyptus”) is not an essential oil product but rather a chemical derived from the distillation of the lemon eucalyptus plant.
Botanical products generally contain one or more of the extracts of Eucalyptus, Citronella, Melaleuca, peppermint or Leptospermum. Botanical products have been shown to provide limited duration of protection.
Repellents do not kill mosquitoes; they prevent mosquito bites by inhibiting the mosquito’s stimuli for blood feeding. Some mosquitoes may be attracted to individuals wearing repellent but mosquitoes will not bite if an effective repellent is used and it has been applied appropriately.
Repellents should be reapplied as soon as any biting mosquitoes are noticed. The estimated reapplication times can be influenced by an individual’s activity, climatic conditions and local mosquito populations. However, over application of a repellent will not increase protection times. Mosquitoes can detect, and bite, areas where no repellent has been applied. Only a small quantity of repellent, applied evenly to exposed skin, is required for effective protection. Do not apply repellents underneath clothing.
Are insect repellents safe?
There is a perception that synthetic repellents such as DEET or picaridin can be toxic to humans. However, despite the widespread use of such products internationally, very few cases of adverse reactions have ever been documented. Serious adverse reactions generally result from gross misuse of repellents such as ingestion, ocular exposure or excessive application particularly on young children. It should be remembered that botanical based products also have the potential to cause skin irritation.
Other methods of personal protection
Electronic vaporiser units release insecticides (e.g. synthetic pyrethroids) from slow-release mats or liquids and can be very effective indoors or in sheltered outdoor areas
Mosquito coils containing insecticides (e.g. synthetic pyrethroids) can be effective in sheltered outdoor areas but are generally not recommended for indoor areas. Coils containing only botanical products (e.g. citronella) offer less protection.
Insecticides (e.g. synthetic pyrethroids) in the form of knockdown aerosols or residual surface sprays may assist in providing protection indoors. The application of insecticides onto the outside of buildings and/or terrestrial vegetation as “barrier treatment” has been shown to provide some protection for the homeowner. Electronic devices that purport to repel mosquitoes with sound (e.g. ultrasonic devices) have repeatedly been shown to be ineffective and should not be used. Commercial mosquito traps vary greatly in their efficacy. There is no evidence that the operation of these traps around the home or garden will prevent mosquito bites. Traps that primarily use UV light will not generally collect many mosquitoes but rather large numbers of non-biting insects.
Treatment of mosquito bites
The classic “mozzie bite” is an itching, inflamed lump on the skin and is an allergic reaction to the saliva injected by the mosquito during blood feeding.
The severity of the reaction is highly variable between individuals and may be determined by a person’s sensitivity as well as prior exposure to mosquito bites. Clean and dry the bite with warm soapy water and a clean cloth. Application of a cool compress (i.e. icepack wrapped in cloth) can reduce inflammation.
The application of a medication lotion (e.g. anti-inflammatory, anti-puritic) or soothing substance (e.g. aloe vera) may reduce itchiness and the use of an antiseptic cream will prevent secondary infection. If secondary infection occurs, consult a medical professional for specific advice. Severe reactions may need to be treated with topical or oral antihistamines but consult a medical professional for specific advice.
Many home remedies exist for the treatment of mosquito bites. The application of a paste comprised of a mixture of baking/bi carb soda and water is thought to offer some relief from itching but there are no scientific studies to support this treatment. Care should be taken if applying essential oils (e.g. lavender or eucalyptus) directly to the skin as these products may result in secondary skin irritation.
The following information is sourced from “The Conversation”. The Conversation is a collaboration between editors and academics to provide informed news analysis and commentary that’s free to read and republish.
Why do mosquitoes suck?
Only female mosquitoes bite. Blood provides a perfect nutritional boost for egg development but who or what mosquitoes bite varies with species. Many mosquitoes opportunistically bite whatever warm blooded creature is about. That includes people. Some people more than others.
Mosquitoes aren’t “dirty syringes”. They don’t pass on pathogens through infected droplets of blood. When mosquitoes insert their mouthparts into our skin, it’s not like they’re sticking in a drinking straw. There are some tubes that suck and some tubes that spit. The spit they inject contains a mix of chemicals, some help get the blood flowing and some make their bite a little less noticeable. Unfortunately, that spit may also contain virus.
If a mosquito sucks up a virus-filled blood meal, that virus must then escape the gut and spread throughout the body of the mosquito until the salivary glands are infected. This process can take from a few days to over a week. But time isn’t all that matters. There is no malicious intent in mosquitoes transmitting viruses. The viruses are simply taking advantage of the mosquitoes’ evolutionary initiative to exploit vertebrate blood.
The viruses don’t make the mosquito sick, that wouldn’t make sense as the virus wants to make sure it makes it to the next host. Unfortunately, humans can fall ill following the injection of a mouthful of virus filled mozzie spit.
Why mosquitoes seem to bite some people more
There are hundreds of mosquito species and they all have slightly different preferences when it comes to what or who they bite. But only females bite; they need a nutritional hit to develop eggs.
Finding someone to bite
Mosquitoes are stimulated by a number of factors when seeking out a blood meal. Initially, they’re attracted by the carbon dioxide we exhale. Body heat is probably important too, but once the mosquito gets closer, she will respond to the smell of a potential blood source’s skin.
Studies have suggested blood type (particularly type O), pregnancy and beer drinking all make you marginally more attractive to mosquitoes. But most of this research uses only one mosquito species. Switch to another species and the results are likely to be different.
There are up to 400 chemical compounds on human skin that could play a role in attracting (and perhaps repulsing) mosquitoes. This smelly mix, produced by bacteria living on our skin and exuded in sweat, varies from person to person and is likely to explain why there is substantial variation in how many mozzies we attract. Genetics probably plays the biggest role in this, but a little of it may be down to diet or physiology.
One of the best studied substances contained in sweat is lactic acid. Research shows it’s a key mosquito attractant, particularly for human-biting species such as Aedes aegypti. This should act as fair warning against exercising close to wetlands; a hot and sweaty body is probably the “pick of the bunch” for a hungry mosquito! Probably the most famous study about their biting habits demonstrated that the mosquitoes that spread malaria (Anopheles gambiae) are attracted to Limburger cheese. The bacteria that gives this cheese its distinctive aroma is closely related to germs living between our toes. That explains why these mosquitoes are attracted to smelly feet. But when another mosquito (such as Aedes aegypti) is exposed to the same cheese, the phenomenon is not repeated. This difference between mosquitoes highlights the difficulty of studying their biting behaviours. Even pathogens such as malaria may make us more attractive to mosquitoes once we’re infected. ￼
Only females bite because they need a nutritional hit to develop eggs. Sean McCann/Flickr, CC BY-NC-SA Researchers are trying to unscramble the irresistible smelly cocktails on the skins of “mosquito magnets”. But the bad news is that if you’re one of these people, there isn’t much you can do about it other than wearing insect repellents.
The good news is that you may one day help isolate a substance, or mixes of substances, that will help them find the perfect lure to use in mosquito traps. We could all then possibly say goodbye to topical insect repellents altogether.
Attraction or reaction?
Sometimes, it’s not the bite as much as the reaction that raises concerns. Think of the last time the mosquito magnets in your circle of friends started complaining about being bitten after the event where the purported mosquito feast took place. At least, they appear to have attracted more than the “bite free” people who were also at the picnic, or concert or whatever.
But just because some people didn’t react to mosquito bites, doesn’t mean they weren’t bitten. Just as we do with a range of environmental, chemical or food allergens, we all differ in our reaction to the saliva mosquitoes spit while feeding.
People who don’t react badly to mosquito bites may think they haven’t been bitten when they’ve actually been bitten as much as their itchy friends. In fact, while some people attract more mosquito bites than others, there’s unlikely to be anyone who never, ever, gets bitten.
The problem is that people who don’t react to mosquito bites may all too easily become complacent. If you’re one of them, remember that it only takes one bite to contract a mosquito-borne disease.
Finally, there is no evidence from anywhere in the world that there is something you can eat or drink that will stop you being bitten by mosquitoes. No, not even eating garlic, or swallowing vitamin B supplements. Perhaps if we spent as much time thinking about how to choose and use mosquito repellents as we do about why mosquitoes bite our friends and family less than us, there’d be fewer bites all around.
Ticks inhabit the Pittwater area and can cause problems for humans and animals.
Most tick bites are harmless, however Ixodes holocyclus (commonly known as the “Paralysis tick”) may make you sick in several ways:
- A range of minor to major allergic reactions, even anaphylaxis.
- The development of allergy to red meat, often anaphylaxis. About two new people with tick-induced red/mammalian meat allergy present at Royal North Shore Hospital every week and there are over 750 sufferers in northern Sydney alone.
- Rare life threatening paralysis.
- There are four stages; the egg, larvae (0.5mm), nymph (1.5mm) and adult (3.5mm).
- Tick stages are seasonal, with larvae active during autumn, nymphs in winter, and adults in the spring.
- The adult stage is the most dangerous, but any stage can lead to allergic reactions.
- Bandicoots are the main carriers.
- Ticks do not jump up from below or drop down from high trees – they “quest” by climbing no more than about 1.5 metres on vegetation (they dry out if they go too high) and sit, waving their front legs to latch onto passers-by.
- As they climb your body, they will stop at tight clothing – hence concentrations of bites occur along underwear lines. If they do not meet any insecticide or tight barrier, they may climb to the neck and head.
- It is best to kill them on the body and let them drop off or later brush them off. It is not helpful for non-experts to pull them off/out, because the trauma may cause more of their saliva to enter the bite and add to the health problems;
- Try to avoid peak ‘ticky’ times, especially after wet periods.
- Wear light-coloured clothing to help spot ticks, and check yourself regularly.
- Tuck pants into socks, and shirts into pants.
- Apply repellents to the skin. Use those that contain DEET or Picaridin, and apply (and reapply) as per label directions. DEET is in products such as RID, Tropical RID, Tropical Aerogard or Bushmans. Picaridin is in products such as OFF.
- Ticks do not like dry conditions! Keep overhanging foliage and leaf litter to a minimum,
- Apply insecticides to areas where ticks occur. Ensure that ticks are on the insecticide label.
- Regularly treat pets to prevent ticks; many dogs die every year from tick paralysis
Getting rid of them
- After being in a ‘ticky’ area, remove clothing and place into a hot dryer for 20 minutes to kill any ticks that may still be present.
- Ticks can be killed by spraying them with a spray that contains ether, which freezes the tick immediately (eg. WART OFF or Wartner). Ether is also an ingredient of Aerostart, the spray that displaces water and enables wet engines to start – but it is not an approved medical substance
- For larval/nymph stage ticks you can apply Lyclear on the tick (an over-the-counter cream available from pharmacies)
- Soak clothing in permethrin washes (available from outdoor stores). Follow label instructions for application and re-application
Removing a tick
Biting midges are often associated with estuarine wetlands.
Biting midges are a group of biting flies that belong to the family Ceratopogonidae. The most significant pest species in Australia are Culicoides ornatus and C. molestus, although other species can become pests when environmental conditions are favourable. Adult biting midges are typically very small (usually less than 4 mm long) and a dark colour. They are characteristically stocky and the pest species often have a distinctive pattern on their wings. Many species are not pests of humans, but some can transmit infectious diseases to cattle and sheep, and are of veterinary importance.
Biting midges are commonly called ‘sand flies’ but, strictly speaking, sand flies are a group of biting insects in the subfamily Phlebotominae. Sand flies are significant pests and vectors of human disease in other countries, but not in Australia.
Biology and ecology
Immature midges develop in moist conditions, including wet soil or organic detritus (e.g. leaf litter), feeding on organic material. Their life cycle takes up to 10 weeks, depending on the climate, and the adults of some species can fly far from their larval habitats. Adult females require a blood meal for egg development.
As a group, biting midges can live in a range of aquatic and semi-aquatic habitats, from estuarine environments to freshwater conditions. The major pest species typically live within the tidal zone and sandy foreshores of rivers and estuaries, and generations of midges are often associated with tide cycles. Coastal developments, such as canal estates, provide favourable conditions for biting midges, but they can sometimes reach pest levels in other coastal and inland environments as well.
Public health importance
Biting midges do not transmit disease-causing microorganisms to humans. However, the nuisance biting of these tiny insects can be severe, especially in areas near coastal lagoons, estuaries and wetlands. Anecdotally, biting midges cause more severe skin irritation than other common biting pests, such as mosquitoes. Reactions to midge bites vary in severity, but there is usually swelling at the bite site, with redness extending a centimetre or more around a central blister. The bites can be extremely itchy and may persist for some days. People living in areas where biting midges are common may become desensitised, so the severity of reactions to bites can decrease over time.
A common myth associated with biting midges is that their urine causes the skin irritation. However, like other bloodsucking insects, midges inject their saliva into the host during blood feeding and this causes an allergic reaction in humans.
There is no specific treatment for biting midge bites. As for other insect bites, a cold compress and soothing lotions or creams will reduce mild reactions. Antihistamines may be required for severe reactions. Take care to avoid secondary infection after scratching the bites.
Personal insect repellents can offer some protection against biting midges. However, in areas with high midge populations, long-sleeved shirts, long pants and head nets provide the most effective protection, especially if they are impregnated with insecticides (e.g. permethrin). Biting midges are most active at dawn and dusk, so avoiding known midge habitats at these times will minimise exposure. In areas where estuarine biting midge species are present, biting is likely to be greatest close to mangroves and in sheltered areas within 2 km of mangroves.
To reduce the number of midges in homes, ensure that buildings have adequate screens on doors and windows. The mesh of the screens must be small enough to exclude these tiny insects (normal fly or mosquito mesh may not be small enough) or the screen should be treated with a long-lasting residual insecticide. Properties with dense vegetation, especially shrubs, are more likely to be affected by biting midges, as the plants provide some refuge and shelter for the midges. Generally, biting midge effects are greatest at ground level and the severity of nuisance biting decreases at higher levels of a building.
Managing the pest and its impacts
Unfortunately, there are very few cost-effective and environmentally friendly options to control biting midges. As the main larval habitats of the most common pest species are in environmentally sensitive estuarine habitats, local authorities cannot apply insecticide or modify the habitat to carry out large-scale control. In most areas of Australia, larvicides are used in canal estates or other habitats close to houses that may not have a high environmental conservation value.
Barrier treatments that protect residential properties close to biting midge habitats are common. These treatments involve applying a residual insecticide to the outside of houses or surrounding vegetation. While this does reduce local biting midge populations, the nontarget impacts should also be considered, such as effects on bees, moths, butterflies and other insects that may contact treated surfaces, as well as on aquatic vertebrates and invertebrates, should the insecticides run into waterways.
- Australian Museum — Biting Midges