Distribution
The common housefly (Musca Domestica) is a ubiquitous pest species with a flight range of at least 8 kilometers (5 miles). It is extremely active indoors. In cold climates, breeding usually ends before winter, and houseflies enter the winter in the pupal or adult stage. However, in warm environments, common houseflies remain active and continue to breed throughout the year.
Lesser houseflies (Fannia canicularis) are often found in poultry farms. They have an erratic flight pattern and are often seen flying in large numbers around indoor light sources. Lesser houseflies tolerate cold weather conditions better than common houseflies.
This species spends the winter mainly in the form of pupae, but as with the common housefly, adults remain active and continue to reproduce throughout the year in warm conditions.
Why Should They Be Controlled?
Common houseflies can spread intestinal worms or their eggs and are potential carriers of diseases such as dysentery, gastroenteritis, typhoid, cholera, and tuberculosis. They are frequently seen on and feed on liquefiable foods that can be moist, decaying materials or food stored for human consumption.
Flies contaminate food by vomiting digestive juices and stomach contents onto food. This "liquid" is then sucked up by the sucking mouthparts, and the fly takes in pathogenic organisms in this way, and these organisms are transferred in contact with other surfaces or survive by traveling through the intestines to accumulate as fly specks. Fly spots formed while the fly is feeding or defecating, like eggs at the point of sale, cause contaminated farm products to be rejected. Flies are also a frequent complaint of environmental health authorities because they cause significant problems, including infestations originating from breeding sites such as garbage dumps or animal shelters.
Lesser houseflies fly longer distances and spend less time resting than the common housefly. Females of this species tend to stay near breeding sites, while only males migrate. For these reasons, F. Canicularis is less likely to spread diseases than M. Domestica, but large populations and similar feeding habits mean that this housefly can also have significant potential to act as a vector of disease. This species has occasionally been described as a vector of intestinal or urinary myiasis.
Control Methods
Houseflies have rapid, prolific breeding habits and high morbidity. Control methods to break the life cycle of houseflies should address both larvae and adult houseflies.
a) Hygiene/management
Adequate hygiene is necessary to limit potential breeding sites and food sources.
- Household waste: Household waste should be kept in tightly closed bins and transported to disposal areas without undue delay. High-risk materials should be kept in bags and incinerated whenever possible. Landfills should be covered with at least 230 mm (9 in) of soil and then compacted. This practice will minimize the emergence of adults and increase the fermentation temperatures at which the larvae cannot survive.
- Farm manure: Manure should be kept as dry as possible, especially in poultry houses, where nutrients in leaking water create ideal, humid breeding conditions. The biothermal method used in the storage of animal manure involves compacting the manure into a cube-shaped pile and is a particularly suitable method for horse manure. This method of storage provides a permanent fermentation, for example, which is lethal to larvae in manure. Tarpaulins can also be used to cover the piles to prevent egg laying and maintain the fermentation temperature.
Adult houseflies can be prevented from entering buildings by using 1.18 mm diameter fly screens (easily removable for cleaning), curtains, mosquito nets or rubber-winged self-closing doors.
b) Insecticides
For best results, an integrated control method containing residual insecticides and baits attractive to houseflies should be applied together with good hygiene.