[The effects of malathion, fenitrothion and propoxur on the house fly, Musca domestica I. (Diptera: Muscidae), populations].

The present work was carried out to determine the LD50 and LD90 of Malathion, Fenitrothion and Propoxur for the house fly, MUSCA DOMESTICA L., under laboratory conditions. The house fly populations were collected from the municipality garbage area of Ankara in September 1981, April and September, 1982. The resistance tests were applied on both sexes by means of Topical Application method. The highest resistance level for Malathion was observed in Ankara strains. The values of LD50 were 261.1, 302.1, 312,6 micrograms/female, respectively. The populations were not showed high resistance ratio to Fenitrothion (R/S 93.3, 126.6, 56.6 at LD50) and Propoxur (R/S 34.2, 31.4, 21.4 at LD50). It is clear that, Propoxur was more toxic to female and male flies than Fenitrothion. However the males were more susceptible to the applied insecticides than the females. It was concluded that susceptibility of houseflies to the insecticides varied widely by seasons in the same habitat. The results of the tests indicated that the resistance level of Malathion was very high. Therefore it should not be recommended for the control of houseflies in Ankara.