Fly species

Flies can regularly be found in homes and businesses across New Zealand.

Some species are more common than others and are attracted to different environments suited to their natural habits and lifecycle.

Knowing about the size, habits, seasonality and lifecycle of different fly species, can help to identify the most effective prevention and fly control methods.

FACT: On average, the adult housefly will live for around 30 days. They go through a complete four-stage cycle that consists of egg, larva, pupa and adult stages.

House fly

(Musca domestica)

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.

Key Facts

• 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.

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

Blow fly, (Bluebottle)

(Calliphoridae family)

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.

Key Facts

• 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.

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.

Cluster fly

(Pollenia rudis)

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.

Key Facts

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

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.

Sand fly

(Spiriverpa lunulata)

Adult sand flies can be a real biting nuisance. They live on sandy riverbanks with an open habitat free of shading trees.

Females prefer to lay their eggs in damp soil or in the water.

Key Facts

• Adult — 10–11mm long.
• Body has a pale grey colour.
• Eyes are bronze–brown.
• Legs are dark reddish–brown.

Lifecycle

• The larvae can take up to two years to develop and live in loose sand.
• In the pupal stage the larvae curls into a circle or “u” shape lasting one or two weeks.

Drain fly

((Psychodidae family)

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.

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.

Lacewings

(Chrysoperla carnea)

Lacewings are considered an important predator of mealybugs in both greenhouses and interior plantscapes.

They also feed on (among others) several species of aphids, spider mites (especially red mites), thrips, whiteflies, small caterpillars and beetle larvae.

Adults are active fliers, particularly during the evening and at night. They have a characteristic fluttering flight.

Key Facts

• Approx 12–20mm long.
• Adults are pale green.
• Long antennae and bright, golden eyes.
• They have large, transparent, pale green wings and a delicate body.

Lifecycle

They feed on pollen and also need nectar or honeydew as food before laying eggs.

• Oval shaped eggs are laid at the end of long silken stalks. These single eggs start off green and turn grey after a few days.
• The active larvae are grey or brownish. They are alligator–like with well–developed legs and large pincers with which they suck the body fluids from prey insects such as aphids.

Lacewings are often used as a biological integrated insect control program.

Fermentation or vinegar 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.