Insects of medical importance

The most dangerous insect is the mosquito.

There are just over 100 species in the NT. Some feed on animals such as reptiles, frogs or birds, while others will feed on mammals, marsupials and people.

About 20 species in the NT bite people often enough to be labelled serious pests. Some carry viruses that can cause disease.

For more information, read common mosquitoes in the NT from the Department of Health ePublications.

Salt marsh mosquito

The northern salt marsh mosquito, Aedes vigilax, is the most important pest mosquito in the Top End because of its aggressive biting habits during the day and night.

It can carry and transmit Ross River virus and Barmah Forest virus disease in the NT. You need to protect yourself to avoid being bitten. The highest risk period for these diseases is from December to March.

Get the salt marsh mosquito pest calendar from the Department of Health ePublications.

• Salt marsh mosquito pest calendar for coastal NT 2024 PDF (798.1 KB)

Common banded mosquito

The common banded mosquito, Culex annulirostris, is the most important disease-carrying mosquito in the NT.

The mosquito is active after sundown and can carry and transmit the following viruses in the NT:

• Ross River
• Barmah Forest
• Murray Valley encephalitis
• Kunjin virus disease.

You need to protect yourself from being bitten. The highest risk period for these diseased is from December to July.

Treating a mosquito bite

If you are bitten by a mosquito, don't scratch the bite as this can lead to infection. You can use ice or buy creams and gels that contain antiseptic and a local anesthetic, which helps soothe the bite.

If the swelling becomes excessive and itchy, you may need to take an antihistamine as well. You should ask your pharmacist.

If the bite becomes infected, you should visit your local general practitioner (GP) to make sure they give you the right medication.

Read more about how to protect yourself against mosquitoes.

The mangrove biting midge, Culicoides ornatus, causes widespread pest problems in mangrove areas along the NT coast.

The midges that are found around mangroves only fly in high numbers about 1.6km from mangrove areas.

Biting midges do not transmit disease to humans in Australia, but they cause an itchy bite that can sometimes become infected.

Get the biting midge pest calendar from the Department of Health ePublications.

• Biting midge pest calendar for coastal NT 2024 PDF (779.1 KB)

There are other insects and spiders that can cause painful and annoying bites and stings or medical conditions in the NT.

These include the following:

• bed bugs
• centipedes
• flies
• honey bees
• itchy caterpillars
• lice
• march flies
• mites - read about scrub typhus
• scorpions
• spiders
• stinging caterpillars
• stinging ants
• wasps.

Most of these rarely cause serious or longer-term after effects.

However, some can cause anaphylactic shock. This is an extreme, often life-threatening allergic reaction.

You can also read the following on the Department of Health website:

• Bites and stings in the Top End and how to avoid them
• Stinging and itchy caterpillars of the Top End of the Northern Territory
• Personal protection from mosquitoes and biting midges
• Mosquito species recorded from the Northern Territory
• Medically important insects in the Northern Territory and how disasters may affect them
• Biting midges or sandflies in the Northern Territory 
• Guidelines to prevent fly breeding in domestic situations in the Top End of the NT.