Biting midges and sandflies

Overview

Biting midges, also known as sandflies, can be a bit of a nuisance to those living in beautiful coastal areas like Byron Bay and the surrounding area.

Midges are very active during dawn and dusk, and the problem is most prevalent in suburbs located close to mangroves and inter-tidal zones.

Unlike mosquitoes, biting midges leave a large raised mark on the skin that is filled with damaged tissue and saliva (containing anticoagulants). These biting insects are annoying, but are not likely to transmit disease.

Biting midges become a public health issue when residential property developments occur close to midge-breeding sites resulting in increased human – midge interaction. The biting midge problem within the Byron Shire community has not been quantified.

How to reduce biting midge problems

Here's some tips on how you can alleviate or minimise midge problems.

If you live in or visit active midge areas:

  • Use personal insect repellents applied to the skin and clothing to give several hours’ protection. Sensitive individuals or young children not wishing to use commercial repellents can try liberal applications of baby oil to exposed skin to reduce bites. An effective home repellent can be made up with equal parts of baby oil, Dettol and an aromatic oil such as citronella or lavender. Local research has shown that oil extracted from the lemon scented gum Eucalyptus citriodora is also a good midge repellent. 

  • Try vitamin B1 (thiamine), as this vitamin has an anti-histamine type action. This will prevent acute allergic reaction and allow the body to develop its own immunity to midge bites. Biting midge expert, Dr Eric Reye, suggests an adult dose of 200mg twice a day with meals, preferably starting two weeks before exposure to midge. As immunity is developed this dose can be reduced. The development of personal immunity generally comes with a regular exposure to low numbers of midge bites, not occasional heavy exposure. Persons who have a more acute reaction to midge bites may require anti-histamine drugs at times. You should consult your family doctor before trialling these drug therapies.

  • Wear light long sleeve clothing when outdoors during midge activity periods, usually early morning and late afternoon, to minimise exposure to these insects.

 Around the home:

  • Keep vegetation surrounding the house to a minimum. This reduces insect harbouring areas and increases air flow surrounding the house.

    • Keep lawns well mown as any activity that reduces sheltering sites and lowers humidity surrounding the house will help to deter midges
    • Landscaping with tallish vegetation with an upper tree canopy is preferable to low, dense vegetation in midge prone areas as it allows a much better airflow near ground level.
  • Install ceiling fans or other air circulation devices that increase air flow inside the dwelling as midges do not like to seek blood meals when a moderate breeze is blowing.

 Outside:

  • Use mosquito coils or plug in insecticide tablet burners during periods of severe midge nuisance.

  • Avoid outdoor activities like car washing and gardening during the early morning and late afternoon when midges are most active as water hosing and digging soil attract biting midge.

  • Reference the lunar cycle before planning an evening barbecue as biting midges are most active in the few days following the full and new moon, especially in the warmer months.

  • Use synthetic pyrethroid barrier sprays applied around vegetation and exterior walls to reduce midge adult numbers around treated premises for many weeks.

Insect trapping devices that use ultra violet light are generally useless for decreasing biting midge numbers in suburban yards. Traps using carbon dioxide as an attractant must be well designed and operated as well as strategically placed to have any possible beneficial effect.

About biting midges

Biting midges are insects that breed in wet soils in the tidal zones such as mangrove mud and sandy shores. They play an important role in our valuable estuary tidal marsh and mangrove ecosystems. Biting midges are attracted to human habitation and rest on screens, fences and vegetation while waiting to take a blood meal. The small insect is easily blown about by prevailing winds, so they prefer dull still days with high humidity when seeking a meal.

Midges activity in Byron Shire

There are four species that have been identified as the main cause of midge problems on the North Coast of NSW. However at this time Council has no data on the particular species involved in Byron shire, the extent of breeding sites or the size of this problem in general.

A sensible precaution to prevent biting insect attack is to avoid areas that are known to have high biting insect activity. Extensive areas of mangroves or estuarine areas with sandy beaches are potential sources of sand flies and generally residents within 400m of the breeding area can be exposed.

The use of any pesticides in such sensitive ecological environments is not supported as it is highly likely to cause serious environmental harm.