Fly species

Flies can regularly be found in homes and businesses across Australia. Some species are more common than others and are attracted to different environments suited to their natural habits and lifecycle. Knowledge of the habits, seasonality and lifecycle of a fly species helps in choosing the most effective prevention and control methods. These are described below.

The fly species that are common pests in Australia are:

• Blow fly, (Bluebottle)
• Bush fly
• Cluster fly
• Drain fly
• Fermentation fly
• Flesh fly
• Fruit fly
• House fly
• Lacewings
• March fly, (Horse fly)

Blow fly, (Bluebottle)

(Calliphoridae family)

Appearance

• Adult is 1/4" - 1/2" in length.
• Metallic blue colour.
• Larva — Similar to the house fly larva in all respects except size. 3/4" when mature. They take 7 – 12 days to mature.

Life cycle and habits of the blow fly

Lifecycle

• Eggs hatch 0 – 18 hrs (partial development may occur within the female).
• Breeds in mostly meat derived substances, sometimes cheese.
• Common pest of dead rodents/birds etc.

Habits

• Bluebottle flies (also known as Blow fly) can often be seen hovering around dustbins. These scavengers are attracted to pet faeces and dead animals and as such are known carriers of disease. 

• Their name originates from their iridescent colours that are similar to coloured bottles.

Bush fly

(Musca vetustissima)

Appearance

• 2-6mm long. 
• Similar in appearance to the house fly but smaller.

Life cycle and habits of the bush fly

Lifecycle

• Only last 2-5 weeks. 
• Eggs are inserted into the excrement of large animals (especially grazing animals). 
• Eggs usually hatch within a day and the larvae usually leave the feeding medium to pupate in adjacent soil.

Habits

• Adults seek large animals, including humans, and remain on and around them for hours at a time being attracted to sweat, tears, saliva and in cases of grazing animals, faeces. 
• Transmit eye infections to humans and livestock and may also transmit other enteric diseases to humans.

Cluster fly

(Pollenia rudis)

Appearance

• 6–10mm in length.
• Dark grey–olive thorax clothed with crinkled golden–brown hairs.
• Wings overlap when at rest.
• Sluggish in flight.

Life cycle and habits of the Cluster fly

Lifecycle

• Eggs laid in soil in late summer or early autumn.
• Larva develop in earthworms – feeding on their host for several days. Then they molt and pupate in the soil.
• Development time from egg to adult is about 27 to 39 days.

Habits

• Cluster flies are commonly found in quiet, undisturbed parts of your home, such as attics and wall voids. They require warm places to hibernate over winter.

• You may see a large group of cluster flies around a window, as they are attracted to the light on sunny winter days.

Drain fly

((Psychodidae family)

Appearance

• 2mm in length.
• Tan coloured body appears as grey.
• Wings densely covered in hair and held tent–like over the body when at rest.

Life cycle and habits of the Drain fly

Lifecycle

• Eggs hatch 1–6 days.
• Larvae 10–50 days to mature.
• Pupae 1–3 days to mature.

Habits

• Drain flies are often associated with sewage beds, where larvae feed on sludge–like organic matter. They are also known by a variety of names; drain fly, sewage fly and moth fly are a few examples.

Fermentation fly

(Fermentation fly)

Appearance

• 1/8" in length. Yellow–brown or mottled in colour with bright red eyes. 
• Abdomen hangs down in flight, which is slow. 
• Tend to hover.

Life cycle and habits of the Fermentation fly

Lifecycle

• Female can lay up to 500 eggs. 
• Develops to adult in about 7 days. 
• Adult only lives for about 2 weeks.

Habits

• Breeds in fermenting residues found in pubs, fruit & vegetables, breweries, etc. 
• Larvae feeds on bacteria and yeast in rotting fruit and veg. 
• May also breed in unclean drains and cleaning utensils.

Flesh fly

(Sarcophagidae)

Appearance

• 6-14mm long. 
• Thorax is light grey and has 3 dark longitudinal stripes. 
• Abdomen is also light grey, spotted with dark patches to give a checker board appearance.

Life cycle and habits of the Flesh fly

Lifecycle

• Lifecycle lasts for 2-4 weeks. 
• The female deposits live larvae on a suitable feeding medium (this can range from spoilt meat or fish, or animal excrement, or in decaying food waste found in garbage bins). 
• Larvae feed for a few days, then move away from the feeding medium to pupate in adjacent drier parts.

Habits

• They are attracted to decaying wastes, excrement and human foods – making a threat to human health.

Fruit fly

(Drosophila species)

Appearance

• 3mm in length.
• Yellow–brown or mottled in colour.
• Bright red eyes.
• Abdomen hangs down in flight, which is slow.
• Tend to hover.

Life cycle and habits of the Fruit fly

Lifecycle

• They can breed in rotten fruit, unclean drains and even cleaning utensils.
• Develops to adult in 7–30 days.
• Adult lives 2–9 weeks.
• In ideal temperature conditions, fruit flies can complete their development in as little as 1 week.

Habits

• Fruit flies are commonly found infesting fruit or hovering around fermenting residues found in pubs, fruit orchards & vegetables plots and breweries

House fly

(Musca domestica)

Appearance

• Adult is 5–8mm in length.
• Grey thorax with 4 narrow stripes.
• Buff or yellow abdomen.
• Covered with small hairs that serve as taste organs.
• Complex compound eyes – with thousands of lenses allows them a wide field of vision.
• 4th wing vein bent and wing tips slightly pointed.
• Larva is white and tapers to a point at the head end. There are 2 spiracle “spots” at the hind end, is legless and 12 mm in length when mature.

Life cycle and habits of the House fly

Lifecycle

• House flies are able to quickly mature from an egg to an adult. They breed in moist decaying vegetable matter eg. in uncovered dustbin or pet food.

• Eggs are laid in batches of 120 to 150 and can hatch in 8 – 72 hours.
• The larvae of House Flies can take 3 – 60 days to mature.
• Pupae matures in 3 – 28 days.

• Once indoors, house flies can be found resting on walls, floors or ceilings. Outdoors they can be seen on plants, the ground, fences, compost heaps and rubbish bins.

  At night them they prefer to rest near food sources approx. 5 to 15 feet off the ground.

Habits

• House flies are major carriers of disease and can infest all types of premises. They are attracted to all types of food, including human food, pet food, animal feed, food waste and even faeces. Seeing adult flies is usually the most common sign of activity and a potential problem. Larvae may also be seen as they crawl out of breeding material to pupate.

Lacewings

(Chrysoperla carnea)

Appearance

• Adults are green
• Around 15–25mm in length.
• Have 4 large ‘lacey’ wings.
• Wings are transparent, with more vertical than horizontal veins
• Have long antennas
• Golden metallic eyes

Life cycle and habits of the Lacewing

Lifecycle

• Their lifespan averages around 3-4 weeks 
• Lacewings develop through 4 stages: egg, larva, pupa, and adult.
• Adult female Lacewings lay up to 600 eggs. Each egg sits on the end of a slender stalk.
• Larvae range in size from 2 mm at first emergence to 8 mm just before they pupate.
• Egg to adult development requires about 4 to 6 weeks when temperatures are warm.
• After hatching, larvae develop through 3, increasingly larger instars before pupating on plant surfaces or under loose bark.
• Adult females start laying eggs about a week after emergence.

Habits

• Green lacewings occur in gardens, tree and field crops, landscapes, and wildlands.
• Adults feed on honeydew, plant nectar, and yeasts; some additionally are predaceous (e.g., Chrysopa species) while others are not (Chrysoperla species). They also eat apples and will attack newly planted legume seeds.

March fly, (Horse fly)

(Family Tabanidae)

Appearance

• Adults can be up to 25 mm long.
• Black to dark brown in colour with green or black eyes.
• Resembling honeybees, except only have one pair of wings
• The males have contiguous eyes, which easily differentiates them from females where the eyes are widely separated.

Life cycle and habits of the Field Mouse

Lifecycle

• Mating is initiated in the air and completed on the ground where the female then deposits an egg mass sometimes with a shiny or chalky secretion, which aids in water protection.
• Eggs are laid in masses ranging from 100 to 1000 eggs on a vertical surface overhanging water or wet ground favorable to larvae development. The eggs hatch in 5–7 days.
• They overwinter in the larval stage and pupate during the spring and early summer.
• Adult life cycle is 30 to 60 days.

Habits

• Most horse flies are found in brushy or low-lying pasture areas near creeks, streams or tanks that provide damp soils in which the immature stages develop.
• Adult female flies, attempting to lay eggs on host animals, cause horses to flee and resist fly "attacks" (hovering, buzzing and striking), occasionally resulting in injury. Horses, mules, and donkeys are primary hosts.
• Larvae live in the digestive tract, injuring the tongue, lips, stomach lining and intestine of the host animal. They apparently feed on the inflammatory products produced by the host in response to their presence. Infestations cause mechanical injuries and an infected ulcerous condition that progressively starves the host animal