Dr. Murai Éva szerk.: Parasitologia Hungarica 19. (Budapest, 1986)
Parasit, hang. 19. 1986 Insecticide resistance of houseflies (Musca dornestica L.) in Hungary. II. Resistance to organophosphorus insecticides Dr. László SZABÓ Research Institute for Heavy Chemical Industries, Veszprém, Hungary "insecticide resistance of houseflies (Musca dornestica I .) in Hungary. II. Resistance to organophosphorus insecticides" - Szabó, L. - Parasit. hung., _19: 93- 103. 1986. ABSTRACT. The resistance of housefly populations to trichlorfon, dichlorvos (DDVP) and fenitrothion is reported in the present paper. The highest resistance was found to trichlorfon: the resistance index calculated on the basis of the FD50 values was below 50, between 50 and 100, between 100 and 200, and above 200 in 1, 2, 10 and 4 populations, respectively, of the 17 populations tested. The resistance indices calculated on the basis of the LDyg values were much higher, suggesting that in natural populations there are many flies carrying genes responsible for high resistance. Only a few populations exhibited some weak resistance to dichlorvos (DDVP): the resistance index was above 10 for one, between 5 and 10 for two, and below 5 for the remaining, populations. Fenitrothion resistance was moderate or low: only in one population did the resistance index exceed 20, in 3 populations it was between 10 and 20, whereas for the other populations below 10. KFY WORDS. Resistance tests, Musca dornestica I.., local populations, Hungary, WHO/SRS strain, trichlorfon, dichlorvos (DDVP), fenitrothion. It is a fact that most insecticides used for housefly control in the last two decades and even today belong to the group of organophosphorus compounds. Precisely this intensive and wide use might have been responsible for the development of resistance to most organophosphates all over the world. Multiresistance to organophosphates was first reported from Denmark (KEIDING, 1956, 1959, 1965, 1975) and from some parts of the United States (GEORG HIOU et al., 1971, 1972) and Japan (HAYASHI et al., 1971, 1972). In those places dimethoate, ,tetrachlorvinphos and dichlorvos had mostly lost their efficacy. By the end of the ' seventies a large body of data had accumulated on the spread of organophosphate resistance of the housefly in other countries of Europe, Asia and America, and in the ' eighties such data were also received from Africa. As our studies were focused on the trichlorfon, dichlorvos (DDVP) and fenitrothion resistance of housefly populations in Hungary, in the following primarily the most important literature concerning these agents is reviewed briefly. The highest trichlorfon resistance has developed in the socialist countries of Eastern Europe where the agent has been used intensively for as long as two decades. According to the results reported by RUPES et al. (1974, 1976, 1980, 1983), in Czechoslovakia trichlorfon resistance has become widespread and the resistance index often exceeds 1000. The same holds true for the German Democratic Republic (M Ü I ,LER , 1977; RHEINHARDT and ESTHER, 1977). In Romania, BALASZ and ENESCU (1974) found high trichlorfon resistance in two housefly populations. Trichlorfon resistance is widespread also in the Soviet Union but not as much as in the countries mentioned above.
