- Biting midges are not sandflies.
- They are present on all continents except Antarctica.
- The adults are about one (1) to two (2) millimetres long, much smaller than the related mosquito.
- Generation time (life cycle from egg to adult) is probably no less than eight weeks.
- Estuarine midges do not breed in the grass, trees or in soil or sand in the garden; they only harbour in these areas.
- They are not known to be vectors of any human disease in Australia.
- In overcast humid weather, they are known to bite all day and night.
- Only the female bites: she needs a blood meal to fertilise her eggs. They are known as pool feeders because they use their proboscis like a saw to create a tiny hole in the skin into which a pool of blood can flow. Saliva is injected into the pool to help the flow of blood. It is this saliva that causes the allergic reaction and itching.
- Remember that biting midge numbers increase around the time of the full and new moons; it is advisable not to plan outdoor functions that coincide with these times.
Personal reaction to bites varies from a slight redness which disappears in half an hour or less, to severe inflammation. If you react rapidly and the swellings are small, you are reasonably immune so treatment may not be needed. Swelling and itching will soon go away.
For these less severe cases, the following tips may help reduce the effects of bites:
- a hot bath may provide temporary relief
- anti-itching creams or lotions from the chemist are quite effective; do not apply them when the skin is broken
- some insect repellents also give relief to the bite, providing the individual's skin is not sensitive to the repellent
- it has been observed that Vitamin B1 (Thiamine Hydrochloride), taken over a period of more than 30 days before exposure to midges, can reduce the severity of some people's reaction to bites (this is not true of everyone and always consult your doctor before taking any vitamins).
However, if you react hours or days later to a bite, whether you felt it or not, your immunity is poor and you are likely to be more severely affected. If your reaction is very severe, see your doctor.
How to Protect Yourself
Anything you can do to reduce humidity, increase light and air movement will make your house and garden less attractive to midges.
- Avoid gardening or watering in the afternoon and early morning.
- Increase air movement in the house by using electric fans to effectively create an area unsuitable for biting midges, as their activity reduces in wind speeds over six (6) to eight (8) kilometres per hour.
- Spray residual (surface) insecticide on your flyscreens to help deter midges from entering your home.
- Burn mosquito coils inside to also reduce numbers.
- Most insect repellents are effective against midges and should be used whenever you are outside the house. Alternatively, an equal part mixture of baby oil, Dettol and Eucalyptus oil is useful.
- Long sleeve shirts and long trousers made of closely woven materials give good protection; when gardening, a hat and gloves are also a big help.
Reducing Midge Activity in Your Yard
To avoid the heat of the day, midges hide underneath the leaves of the plants and shrubs in your garden. These areas can be treated by applying insecticide on the leaves.
Reminder: re-apply the insecticide after heavy rain or when midge activity increases.
Chemical Control Tips
- Natural insecticides/Pyrethrum: available from most plant nurseries and hardware stores. Pyrethrum has little residual capacity, so applications may be needed on a regular (weekly) basis during problem periods.
- Chemical insecticides: common garden sprays containing Permethrin are effective for a longer lasting effect.
Gardening or hosting a barbecue? Parrafin oil or perfumed lamp oil can be mixed with either citronella or lavender oil and burned in 'Polynesian' bamboo lamp burners placed upwind of your activity. Mosquito coils can also be effective.
What is Council Doing?
Council's Pest Management Unit conducts regular monitoring and surveillance programs of the larval biting midge populations throughout canal systems and waterways on the Gold Coast. When biting midge populations are in a susceptible stage, the Pest Management Unit conducts control programs, using a boat fitted with a boom spray to treat the inter tidal beaches.
Additionally, Council conducts adult biting midge control by misting with the natural insecticide Pyrethrum in areas of the city, to reduce the biting midge numbers to an acceptable level. Council's policy is to conduct Pyrethrum misting programs based upon residents' requests and is timed to coincide with peak midge emergence events.
How Can You Help Council?
Catch some of the midges while they are actually biting. This can be done by getting a small jar of methylated spirits and moistening your finger with the methylated spirits. Place your finger on top of the insect and then wash the insect off your finger into the jar with the methylated spirits. Having done this, phone the Pest Management Unit of Council and they will arrange to pick up the sample for identification of the nuisance species.