HIGH Irritation

December, January, February  –   March & April (depending on rain)

Medium Irritation

March, April – October, November

Moderate Irritation

May, June – August, September

Low Irritation


Facts About Flies

While there are over 120 000 species of flies, this reference guide will concentrate on the 4 species which represent the vast majority of the problems for humans and animals:

House flies, Stable flies, Blow Flies, and Culicoides midges.

Flies have been around as long as mankind and have been found in seven continents.  It has been documented that the fly transmits deadly diseases such as typhoid fever, dysentery, cholera, anthrax, leprosy and tuberculosis just to name a few.  In many instances, flies are the indirect cause of low livestock weights and poultry deaths.

A Fly is born

During a fly’s lifetime (usually a 30-day cycle), a female fly will lay anywhere between 100-600 eggs.  Each fly egg hatches into a small, grub-like, creature (larvae), which looks like a small worm rather than a fly.  By eating nutrients from soil, ponds or even in the sea, larvae will grow to adult fly size within a few days.

  • Some Other Facts About Flies:

Flies have over 4 000 facets for sight in each eye.

Flies are attracted by movement more than colour.

Flies have a smelling distance of over 700 metres.

A fly’s feeding range is usually limited to approximately 3 kilometers.

A single garbage can, if not emptied, can be the breeding ground for 30 000 flies.

During warm weather, a fly can produce a family generation in less than two weeks.

Types of Flies

There are several different kinds of flies that are common around farms, residential areas and food-handling establishments.

  • House Fly

The housefly, Musca domestica, is one of the most common of all insects.  It is a worldwide pest in homes, barns, poultry houses, food-processing plants, recreation areas, etc.

House fly eggs (100 – 150) are laid in almost any type of warm organic material.  Animal or poultry manure is an excellent breeding medium.  Decaying vegetation such as grass clippings and garbage can also provide for optimum breeding conditions.

Houseflies are strong fliers and can become widely distributed by flying, wind currents, vehicles and animals.  Generally, though, flies are abundant in the immediate vicinity of their breeding site. The adult life cycle – is usually ±21 days can be completed in 12 days.

  • Stable Fly

The stable fly, also known as the dog fly, is a blood-sucking fly.  Stable flies primarily attack animals for blood, but in the absence of an animal will also bite humans.

An adult stable fly can fly up to nearly 100 km from their breeding sites.  The stable fly adult is similar to the housefly in size and colour.  The stable fly, however, has a long bayonet-like mouthpart for sucking blood.  Unlike Facts About Fliesmany other fly species, both male and female stable flies suck blood.

Stable fly bites are extremely painful to both man and animal.  When hungry, stable flies are quite persistent and will continue to pursue a blood meal even after being swatted several times. The adult life cycle – is usually 14 – 21 days but can be completed in 7 days. The female lays 600 – 800 eggs.

  • Blow Flies and Bottle Flies

There are quite a few species of blowflies found in and around residences.  Green blow, blue blow, and bronze blow flies may be more abundant in urban areas than houseflies.

Blowflies can breed on dead rodents and birds.  They usually breed in meat scraps, animal excrement and decaying animal matter around houses.  The adult flies are quite active inside and are strongly attracted to light.

The adult life cycle usually lasts 9 – 21 days from egg to adult.

  • Culicoides midges

They are normally night biting, blood sucking insects that become active about half an hour before sunset. Only the female is a blood sucker, and they normally have a life cycle of about 30 days but can complete it in 25 days. The main species proven to transmit African Horse Sickness – C. imicola, lay 60 – 160 eggs per batch.

The midges are strong fliers and very small – thus not easily seen. They normally get into the haircoat and are not seen when sucking. Certain horses show an allergic reaction to the bites, or they are so itchy, they rub against objects and develop bald sports.

Fly Control

Why Pest/Fly Control?

As stated in, flies have been a menace to mankind since biblical times.  The importance of fly control is paramount, if not for health reasons, then for financial ones.

Poultry losses run into the millions of Rands annually and cattle weight has been known to drop 10-15 % due to the ever-irritant flies.

For many years, new chemical pesticides were developed to help control the fly population.  The primary reason for new insecticides (or combinations) was “resistance” to the products on the market.  Resistance is the ability of an insect population to withstand exposure to insecticides.  This is acquired by breeding from insects that have survived previous exposures to a pesticide that did not wipe out the whole population.  The surviving insects breed and develop a resistant strain that survives insecticide treatment.

Methods of Fly Control

There are four primary methods of pest management: cultural control, mechanical control, biological control and chemical control.

  • Cultural Control – Control by changing the human habits to reduce the problem (e.g., move horses into stables at night, pick up animal faeces).
  • Mechanical Control – Eliminate breeding sites, install proper drainage, use traps (e.g., Fly Strings, Red Top traps).
  • Biological Control – Consists of the use, exploitation, or manipulation of one life form to suppress the population of another (e.g., wasps that parasitize fly pupae or keeping free range chickens to eat larvae and pupae).
  • Chemical Control – Use of insecticides.

In most cases, a combination of some or all of these methods may be needed.  This is called Integrated Pest Management (IPM). IPM combines biological, mechanical and cultural techniques with as few toxic chemicals as possible to reduce pest populations to tolerable levels.