Common Fly Species

Flies can regularly be found in homes and businesses across Kenya.

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.

Horse Fly

(Family tabanidae)

Horse flies are a particular pest to livestock. Relentless biting attacks by females can result in reduced weight gain in some animals.

Male horse flies are mainly pollen and nectar feeders and are most active during daylight hours.

Horse fly bites can be very painful for humans too.They have mouth parts that work like miniature knives, which they use to slash open the skin with a scissor–like motion.

Key Facts

  • Adults can be up to 25 mm long.
  • Black to dark brown in colour with green or black eyes.
  • The males have contiguous eyes, which easily differentiates them from females where the eyes are widely separated.
  • Horse fly bites can be very painful.

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 favourable 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.

Bluebottle Fly

(Calliphora vomitoria)

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 30-36mm in length.
  • Metallic blue colour.
  • Larva — Similar to the house fly larva in all respects except size. 19mm 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 seen from April to September. 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.

Life Cycle

  • 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.

Fruit Fly

(Drosophila species)

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

Key Facts

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

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.

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. 1.5-4.5m off the ground.

Drain Fly

(Psychodidae)

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.

Key Facts

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

Lifecycle

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

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 Fly

(Fermentation fly)

Appearance

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

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

(Family - 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.

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.