الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 59 |  |  |
| | | from | 59 | | |
Abstract
It is well known that flies constitute one of the greatest problems to public health. The abatement of fly population is essential to the control of many serious and wide-spread diseases detrimental to the human health.
Many fly species are commonly found in human habitations especially in tropical and sub-tropical regions. They are potential among the most dangerous pests, since they act as vectors for many dangerous diseases. Various endemic diseases in our country such as cholera, trachoma and dysenteries are transmitted by flies.
House flies are among the most common and persistent insects found within human homes. They have a strong interdependent relationship with man, and they travel with human populations to even the coldest regions of the world. They are commonly found in both indoors and outdoors. They thrive on excrement, dead animal bodies, and contaminated areas where fecal matter, large amounts of organic waste and piles of garbage are left exposed and unattended (Sulaiman et al., 1989).
In house flies, liquid food is sucked up and solid food is wetted with saliva so that it could be dissolved before ingestion. Water is a compulsory part of its diet as the fly cannot live without water for more than 48 hours. Other sources of food of house fly include milk, syrup, meat broth and many other materials present in human settlement areas. The requirement for food in house fly is twice or thrice a day (Keiding, 1986).
Flies are responsible for the spread of many diseases as diarrhea, anthrax, eye infections and possibly tuberculosis, typhoid fever, cholera, staphylococcal food poisoning and shigellosis (Connor, 1966 and Sack et al., 1971). Esrey et al. (1991) and Cohen et al. (1991) observed that there was a correlation between fly population and diarrhea, and diarrhea and shigellosis incidence, respectively.
House flies constitute a major problem in a variety of industries, such as food processing industries and food establishments (Ostrolenk and Welch, 1942), poultry, pig and dairy farms (Hansens, 1963 and Axtell and Arends, 1990), they feed on almost anything with nutritional value. Having such a broad preference, they may visit many different food sources, and come into contact with microbe-rich substrates, such as manure or decaying corpses as well as human or livestock food. In doing so, they may transmit pathogens and may be vectors of several diseases.
In addition to transmitting diseases, house flies cause annoyance to man and animals. High population densities of houseflies in poultry farms can cause nuisance to such an extent that chickens reduce their egg production. Furthermore, the faeces of houseflies decrease the aesthetic appearance and value of eggs (Howard and Wall, 1996). Economic losses caused by Musca domestica in poultry houses were reported to exceed 60 million US dollars per year in the United States (USDA Report, 1976). Finally, the swarming of large numbers of house flies, emerging from livestock farms, to neighboring domestic settlements, may result in considerable social and legal problems for farmers (Howard and Wall, 1996).