RESUMEN
The Presence of a large number of. house-flies is a direct indication of the poor sanitary conditions of a particular locality. In the insanitary localities the usual features have been found to be the presence of heaps of refuse and filth scattered here and there due to indiscriminate defaecation, open kitchen wastage, open latrines, meat shops and slaughter houses. In the present study 14,400 house-flies were collected from six insanitary and six sanitary areas of Lahore over a period of one year. The frequency from insanitary and sanitary areas was 21% and 13.98% for the cysts and 16.66% and 10.75% for ova respectively. The frequency of the cysts and ova was found to be significantly higher [P<0.001] in the insanitary areas. It is recommended that sanitary conditions should be improved to minimize the population of house-flies in Lahore