Insect bites and stings

The majority of insects in Australia are not harmful to humans. However, some insects bite and sting if they are threatened so it is best to avoid touching them if you want to avoid being stung or bitten.

Some people are allergic to certain insect bites or venom. In the case of an allergic reaction to bites or stings, medical attention should be sought. Call a doctor or hospital for guidance.

The Australia-wide Poisons Information Centres have a common telephone number: 131 126.

Common biting or stinging insects

Common insects that bite or sting:

Other biting or stinging arthropods

Ticks and mites, spiders, scorpions and centipedes are some other well known biting and stinging arthropods. These animals are not insects.

Bed bugs

Two species of bed bug occur in Australia, Cimex lectularis and Cimex hemipterus. Bed bugs are relatively small insects, about 5 mm in size. The body is dorsoventrally (from back to front) flattened and they have no wings. They have obvious eyes and sucking mouthparts, and are reddish brown in colour. Bed bugs are blood feeders and are most active at night or in the early hours before dawn, but if starved for some time they may be active during the day.

To obtain a blood meal the bed bug pierces the skin of the host and injects saliva. This saliva has anticoagulant properties which makes the blood flow more easily. Bed bugs ingest their meal rapidly only taking 5-10 minutes to engorge themselves. A blood meal is required at each of the five stages of nymphal development. Female bed bugs lay several eggs in small batches, which hatch in about 10 days. Adult bed bugs can live for approximately 6-12 months. Because of their size bed bugs can get into small cracks and crevices.

Reactions to bed bug bites can vary from no reaction at all to severe irritation and localised swelling at the bite site.

Honey Bees

Honey Bee, Apis mellifera, stings are barbed and, when a person is stung, the sting (with venom gland attached) will stick in the skin and tear away from the bee. This injury kills the bee, but the venom gland continues to pump venom through the sting, so it should be removed as soon as possible. Do not squeeze it as this will force more venom into the wound. The sting is best removed by scraping it out with a fingernail.

Most Honey Bee stings cause intense local pain and swelling. However, if a victim is allergic to bee venom, a sting may cause more general symptoms. Most seriously, these can include difficulty breathing and collapse. If a sting victim is known to be allergic to wasp and bee venom, medical attention should be sought immediately.

If you find a swarm of bees, do not approach it. Contact your local beekeepers' association or look up under 'Bee and Wasp Removal' in the Yellow Pages.

European Wasps

European Wasps, Vespula germanica, are more aggressive than bees and will attack when their nests are disturbed. Unlike bees, wasps can sting more than once and do not die after stinging. The sting causes a burning pain and swelling. Ice or cold water should be used to relieve the pain. If a sting victim is known to be allergic to wasp and bee venom, medical attention should be sought immediately.

Biting and non-biting flies

Some biting and non-biting flies can cause problems at certain times of the year. A housefly can carry millions of bacteria in its gut, mouthparts or on its feet.

Scientists have tried introducing various other insects as a means to control fly numbers. For example, dung beetles have successfully been introduced in Australia in areas where high amounts of cow dung have increased fly populations. The dung beetles use cow dung as their food and shelter, breaking up pats of cow dung quickly before fly populations can take hold.

Mosquitoes

Mosquitoes are also biting flies. They can carry diseases such as malaria. This disease is passed on to humans from the mosquito's salivary glands into their human host's bloodstream. In Australia, malaria is not a major health problem, but other mosquito-borne diseases such as Ross River Virus and Murray Valley Encephalitis are of increasing concern.

Head Lice

Head lice, Pediculus capitis, are blood-sucking ectoparasites of humans. This common human parasite does not affect other animals.

An adult head louse is a small six legged insect, 2.5 mm - 3.5 mm in length, with well developed eyes, small antennae and a flattened light brown body. The claws on each leg enable the lice to hold on to hairs, and they can run quickly over the scalp through hair. Head lice live their entire life (about a month) on the head of their host, and are often concentrated towards the back of the head and above or behind the ears.

Head lice suck blood from the surface of the scalp and can feed at any time of the day or night. Without a human host, head lice will only survive a few days. They cannot infest furniture, bedding, pets or other household items.

Transfer of head lice to individuals is most commonly by hair to hair, head to head and close bodily contact. Sharing combs, brushes, ribbons, hair bands, hats, pillows and similar personal articles is another way that lice can spread.

Ants

Several species of ants pose serious health threats to people sensitive to their stings, notably species of Myrmecia (the bull ants and jack-jumpers) and Odontomachus. In extreme cases hospitalisation may be required. There is anecdotal evidence from bush workers that repeated exposure to stings over several years can result in increased sensitivity to the venom. If a sting victim is known to be allergic to wasp and bee venom, medical attention should be sought immediately.

Not all ants have stings.

Ants from the subfamilies Ponerinae (Green Head ants and others), Myrmeciinae (Bulldog ants, Jack Jumpers), and Myrmicinae (includes the introduced Fire ant) all have functional stings. However, many of the most common ants such as the Dolichoderinae (Meat ants, Coconut ants, Argentine ants) and Formicinae (Sugar ants, Green Tree ants) do not have functional stings, and rely on spraying noxious chemicals at potential threats.

Medical information

For medical information about all of these biting and stinging insects (and other arthropods), the Department of Medical Entomology at the University of Sydney has a series of fact sheets on Medically Important Arthropods that assist with identification and treatment.


Dr Dave Britton , Collection Manager, Entomology
Last Updated:

Tags bites, stings, medical, anaphylaxis, anaphylactic shock, bees, wasps, ants, bed bugs, head lice, mosquitoes, mosquitos, flies,

4 comments

Dave Britton - 9.02 AM, 16 February 2011

Hi Nick,

All I can really say is that it is an assassin bug (Reduviidae) – it is a nymph, and unfortunately identification is based on adults, which change considerably in appearance after the final moult from nymphal stages. Nymphs are rarely collected, and do not preserve well in the dry collection as they are comparatively soft-bodied, which makes it even harder when on the rare occasion a series of nymphs are associated with adult specimens.

Nearly all large assassin bugs are capable of biting humans, as they have well developed piercing tubular mouthparts for prey capture. The bites of predacious bugs such as assassin bugs and water bugs are often very painful, as they also inject a small amount of saliva which contains digestive enzymes which are designed to break down proteins in their prey items. Some people certainly react very badly to bites from these bugs. On the positive side, there are no Australian species of assassin bug which deliberately attack humans, and bites nearly always occur from bugs getting accidently trapped in clothing, or when they are held in the hand, so it is an event that is rarely repeated unless you are trying hard!

There are some large assassin bugs which have been used for pest control in agriculture – have a look on the web for articles about Pristhesancus spp. The few pictures of nymphs resemble your photo, but as I said above, I cannot be 100% confident in identifying them from a photo of a nymph.

Adults and nymphs

www.brisbaneinsects.com/brisbane_bugs/CommonAssa.htm

NickW - 9.01 PM, 31 January 2011
My daughter was stung by an assassin bug this evening. At least that's the best match I can find for the bug we caught. Could you please identify which assassin bug this one is (refer photo)? Thanks...

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joeffreypaul - 2.01 AM, 28 January 2011
Where did that head lice came from? Is there any way to stop them? coz it’s kind of annoying when they are living on you, your scalp will be itchy and sometimes you can’t concentrate on your works. The most things are when I was in a meeting and in front of my co investors I scratch my head and I can’t stop it coz it’s so itchy is there any quick head lice treatment that can help me with it.
Ophelia Smith - 5.01 PM, 25 January 2010
Thanks a lot for this information...goes well with my theme Insects.

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