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Kiwicare Fly Control Calendar

Posted in Pest Advice on March 30, 2016

When to Control Flies 

Flies are vectors of a large number of diseases including gastroenteritis, dysentery, typhoid, polio, salmonella and tuberculosis. Others, such as sand flies, horse flies and mosquitoes are a direct irritant, biting humans and sometimes causing painful reactions.

Numerous bristles on the flies' legs pick up and distribute germ-laden particles wherever they go from rotten animal waste to your sandwich or other food.

In warmer climates, breeding continues throughout the year. Eggs are laid in moist decaying animal or vegetable matter and animal waste. The maggots (larvae) of flies feed voraciously on the food matter before pupating and emerging as adult flies.

House Flies

The most common pest flies in homes. Adult house flies are 8-12 mm long. Their thorax is grey or sometimes black, with four longitudinal dark lines on the back. Eyes are usually dark red.  

House flies feed on liquid or semi-liquid substances. The solid material is softened by saliva or vomit before ingestion. House flies will eat many types of food but usually, feed on rotting vegetable matter such as composting lawn clippings and manure.

Because of their large intake of food house flies deposit faeces constantly; one of the factors that make the insect a dangerous carrier of pathogens. House flies are active only during the day and rest in corners or hanging items at night. Preferred resting places can be identified by the build-up of "flyspecks," light coloured spots formed from regurgitated fluid and darker faecal spots.

The maggots of house flies feed voraciously on moist food for 4-7 days before pupating and emerging as adult flies which usually live for 3-4 weeks.

Lesser House Flies

Smaller than ‘standard’ house flies they are 4-6 mm long. The first two segments of the abdomen are dark brown and translucently yellow surface. The lesser house fly is known for its habit of entering buildings and flying in an angular circling flight path near the middle of rooms, often around hanging items such as lights. They may continue this flying all day and only land on surfaces at night.

Larvae of lesser house fly (maggots) feed in all sorts of decaying organic matter including carrion and manure.

Blow Flies

This group of flies is associated with carrion (dead animals) and other protein food sources. Adult flies commonly have a shiny metallic appearance (blue and green bottles). Most are larger than the house flies but there are some smaller species.

Larvae of most blowfly species are scavengers of carrion and dung, and most likely constitute the majority of the maggots found in such material.

Fruit Flies

The fruit flies are also known as vinegar flies and drain flies. Drosophila melanogaster is the common fruit fly and has been used extensively in the science of genetics over the last fifty years because if it rapid breeding habits. These flies are small usually 2-4 mm long.

An infestation of fruit flies suggests rotting fruit or vegetation, stale beer/ wine, blocked drains, or other fermenting sugary material somewhere close by.

Cluster Flies

Cluster flies are medium to large (8-15mm) 'dopey' flies, with a dark grey to black non-metallic abdomen. They are members of the blowfly group and the larvae of the fly feed on earthworms in turf, pasture or lawn areas. Then in late autumn and early winter, the adult flies will move into homes and other buildings to ‘hibernate’ over winter.

They are named cluster flies because of their habit of congregating in large groups or swarms in dark places such as attics, corners of dark rooms, 'nooks and crannies' and 'cracks and crevices'. In large numbers or when crushed the flies release a stale sweet smell. Each fly is thought to release a pheromone (smell) that attracts others. This pheromone will linger on even after all the flies have been destroyed and removed. Therefore the pheromone will continue to attract cluster flies to that area and clusters keep recurring. It is therefore important that residual treatments are continued even when there are no flies present.

The flies congregate to survive through the winter.  Once warmer weather arrives in spring they emerge from their 'hibernation' to lay eggs on surrounding grassland, pasture and lawns. The larvae that hatch from the eggs bore into earthworms, where they feed, eventually killing the worms. Then they pupate and emerge as adult flies. The flies go through as many as five life cycles through summer before the last adult generation of the season looks for somewhere dark, warm and dry to ‘hibernate’ over winter.

Other Flies

There are many other fly species (~120,000) including horse flies, mosquitoes, gnats, midges, sand flies, hoverflies and others.

Some flies including horse flies, mosquitoes, and sand flies bite. But many such as hoverflies are beneficial, eating some of the pests such as aphids that cause problems in gardens.

Fly Control

For the general control of flies follow these steps:

  1. Clear and Clean – Sanitation is the first and foremost step in managing flies.
    Outdoors search for and remove fly breeding sites, fly food sources and dead flies. Clear drains, check compost heaps and bins for maggots and use NO Bugs Super in areas outside where flies congregate. Breeding sites such as compost heaps can be sprayed with NO Bugs Super to kill eggs and maggots. To kill flies in rubbish/recycling bins and to keep them smelling fresh use SORTED cleaners and then NO Bugs Super.
    Indoors remove or cover food that might be attracting flies.
  2. Barriers - Reduce the risk of flies gaining entry to your home. Where possible keep doors and windows closed or fit fly screens. In spring carry out a fly (and spider) treatment around the exterior of buildings; use NO Bugs Super applied to walls, eaves, window and door frames, fences, decks, patios, and other surfaces flies land on. This treatment will need repeated 3 after 3 months.
  3. Control- Treat internal and external surfaces where flies land, including bins, with NO Bugs Indoor or NO Bugs Super long-lasting surface sprays. For a quick knockdown and kill of fly numbers or treatment of flies in roof voids or other spaces use NO Bugs Super Bug Bomb.


  • House Flies (and Lesser House Flies) are often found flying around the middle of rooms or under covered deck areas. They are mistaking the calm air conditions and shade for the areas below tree canopies where they congregate to mate. Changing the airflow and lighting in a room can discourage them from this habit; trial and error may be required to find the most discouraging conditions.
  • Flies will be attracted to the smell of food in kitchens so kitchen waste should be cleared away regularly and bins in kitchens should be clean and have a tight-fitting lid.
  • Exterior waste bins should be kept clean and located away from buildings or entry points.
  • If you have pets ensure their food bowls are cleaned daily and food is not left in the bowls to attract flies. Clear away any animal waste and do not leave it to attract flies.
  • If you are controlling slugs and snails in your garden collect the dead molluscs as they will be used as food by blowflies and others.
  • Do not leave fruit drinks, wine or beer sitting around. Clean glasses soon after use. Wipe up spills of sugary drinks, wine, cider, beer and beer.
  • Rinse bottles and cans before placing in recycling bins and ensure the bin is clean and has a tight-fitting lid.
  • Check fruit in fruit bowls is not rotting. When disposing of rotting fruit seal it in plastic bags before placing it in bins.
  • Check for spillages of food or drink behind fridges/freezers, ovens, larders etc. Clean up.
  • Often not all the possible sources of flies are under your control. Speak to neighbours and combine treatments so that all benefit.
  • Open outward opening louvre windows. Flies are often attracted to the light from windows and are seen battering themselves at the glass in an attempt to ‘get out’. Where flies are seen exhibiting this behaviour and there are outward opening louvre windows to the side or top, open these a little they will act as one-way valves to let flies out but it is unlikely that flies will find their way in.
    Note: Do not open windows where there are more flies outside than in.

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