Studies on the Resistance to Various Insecticides of a House Fly Strain (Diptera: Muscidae) Selected with Azamethiphos K. SAITO, N. MOTOYAMA,' ANDW. C. DAUTERMAN North Carolina State University, Department of Toxicology, Box 7633, Raleigh, North Carolina 27695
J.
Econ. Entomol. 84(6): 1635-1637 (1991)
ABSTRACT A colony of azamethiphos-resistant house flies, Musca domestica (L.), was obtained from Denmark and further selected in the laboratory with azamethiphos for four generations. LD ••s for various insecticides were determined and compared with those of a susceptible house fly strain. The selected flies showed cross-resistance to all insecticides evaluated. The flies were highly resistant to most organophosphorus, carbamate, and chlorinated hydrocarbon insecticides except prothiophos, p,p'-DDT, and the pyrethroids. We conclude that the main mechanisms responsible for resistance are presumed to be factors other than acetylcholinesterase sensitivity and nerve sensitivity due to knockdown resistance. Insecta, cross resistance, azamethiphos, Musca domestica
AZAMETHIPHOS (S-6-chloro-2-oxo-oxazol[ 4,5b]pyridin-3-ylmethyl) O,O-dimethyl phosphorothioate is an insecticide under development by CIBA-GEIGY, Basel, Switzerland. It has shown good activity against adult house flies, Musca domestica (L.), when applied as a paint to cattle, pig, or poultry stalls or buildings, or when applied to the surface of mallure (DPIL 1989). The acute oral LDo".of azamethiphos is 1,180 mg/kg to the rat and 1,400 mg/kg to the mouse. Thus, the compound has a low acute toxicity to mammals. In 1987 and 1988, resistant flies were found on two farms in Denmark (DPIL 1989). The insecticide had been used as paint-on bait for fly control in 1985 and 1986. The development of DDT resistance in the house fly was first reported in 1946 (Brown 1961). Subsequently, organophosphorus resistance in the house fly and the Culex mosquito showed cross resistance to DDT (O'Brien 1967). A decrease in insecticide sensitivity to DDT and pyrethroids is due to the gene Kdr (Tsukamoto et al. 1965, Oppenoorth & ~elling 1976, Miller et al. 1979). Another mechanism responsible for organophosphate and carbamate resistance is a decrease in AChE sensitivity (Smissaert 1964, Rama & Iwata 1971). The purpose of our study was to investigate the resistance pattern of an azamethiphos-resistant strain of house flies after further selection with azamethiphos in the laboratory. Materials and Methods Insecticides. The insecticides used in this study, their purities, and their sources were as follows.
I Current address: Faculty of Horticulture, Chiba University, Matsudo, Matsudo-shi, Chiba-Ken 271, Japan.
Azamethiphos (99.0%) was supplied by CIBAGEIGY, Greensboro, N.C. Fenitrothion (97.0%), diazinon (98.5%), dichlorovos (98.0%), malathion (98.8%), trichlorfon (98.0%), ethion (99.0%), ph osdrin (98.0%), azinphosmethyl (99.0%), propetamphos (89.0%), fenvalerate (98.0%), permethrin (98.0%), and propoxur (99.0%) were obtained from Chern Service, West Chester, Pa. Prothiophos (94.5%) was provided by Nihon Tokushu Noyaku Seizo K.K., Tokyo, Japan. Carbaryl (99.0%) was provided by Union Carbide Corp., Research Triangle Park, N.C. Methyl parathion (98.0%) and p,p'-DDT (99.0%) were obtained from City Chemical Corp., New York. -y-BRC (97.0%) was obtained from Aldrich Chemical Company, Milwaukee, Wis. Fenitrooxon (95.0%) was prepared by reacting dimethyl phosphorochloridate with the sodium salt of 3-methyl-4-nitrophenol (Kasai et al. 1992). Insects. The azamethiphos-resistant 594vb strain (DPIL 1989) of the house fly was supplied by J. Keiding of the Danish Pest Infestation Laboratory, Lyngby, Denmark. Insecticide-susceptible flies of the CSMA strain were obtained from a culture originally supplied by Union Carbide Chemical Company in 1962 and maintained since then at North Carolina State University. The resistant and susceptible strains of house flies were maintained as adults on a diet of milk and sugar at 22-27°C. Selection with Azamethiphos. Selection of the 594vb colony was done by topical application of 0.5-~1 acetone solutions containing azamethiphos to 100 2-d-old female and male flies. Twenty-four hours after treatment, flies that had survived were transferred to a clean cage to mate and produce offspring. Azamethiphos was applied at the rate of 1 ~g per fly in the first generation, 10 ~g in the second generation, and 100 ~g in the third and fourth generations.
0022-0493/91/1635-1637$02.00/0
© 1991 Entomological Society of America
Downloaded from http://jee.oxfordjournals.org/ by guest on June 9, 2016
KEY WORDS
1636
JOURNAL
OF ECONOMIC
Table 1. Selection or 594vb house fly colony with azamethiphos and response or resulting population
Generation I 2 3 4
Azamethiphos applied, I'g/f1y
% Mortality
I 10 100 100
53 67 31 53
Toxicity Evaluations. The toxicity of the various insecticides was determined by topically applying 0.5 /-llof acetone solution of each insecticide to the dorsal surface of the thorax of adult female house flies (3- to 6-d old). At least 20 flies were treated
at each concentration; four to eight concentrations were tested. Control flies were treated with acetone only. The flies were kept at 22-27°C, and mortality was determined 24 h after the treatment. Paralyzed flies were considered dead. LD.os were estimated as described by Bliss (1935). Results and Discussion A summary of the selection of the 594vb colony with azamethiphos is given in Table 1. After the third and fourth generations, the LD50 was > 100 /-lgazamethiphos per fly. This is more than 100fold higher than the LD50 of the original 594vb colony. LDsos of the various organophosphorous insecticides to 594vb and the susceptible CSMA strain are
Organophosphates Azamethiphos Fenitrothion Diazinon
Dichlorvos Malathion Trichlorfon Ethion Phosdrin Azinphosmethyl Propetamphos Prothiophos Methyl parathion Fenitrooxon Organochlorines -y·BHC p,p'·DDT
House fly strainG
n
pyrethroid,
Slope ± SE
± ± ± ± ± ± ± ± ±
and carbamate
insecticides
LDso (95%CL), I'g/2
S R S R S R S R S R S R S R S R S R S R S R S R S R
700 300 120 160 180 180 180 120 160 220 280 140 180 220 120 200 140 140 120 120 100 120 160 120 260 200
4.50 6.85 4.02 2.24 3.93 2.79 4.23 3.63 4.36
0.57 1.54 0.74 0.37 0.74 0.40 0.70 0.66 0.75
0.058 131.2 0.062 20.21 0.062 3.108 0.009 0.116 0.512
3.52 ± 0.47
0.092
2.53 2.43 4.14 1.74 4.45
± 0.38 ± 0.45 ± 0.72 ± 0.26 ± 0.67
0.285 46.10 0.022 2.637 0.133
5.27 1.80 4.06 7.06 4.15 0.98 2.23
± 0.86 ± 0.41 ± 1.00 ± 2.25 ± 0.70 ± 0.26 ± 0.29
0.052 0.720 0.143 0.352 0.017 25.41 0.358
(0.053-0.064) (119.5-144.0) (0.053-0.073) (15.52-26.29) (0.054-0.071) (2.582-3.745) (0.008-0.011) (0.097-0.138) (0.446-0.588) >200 (0.082-0.105) >150 (0.226-0.355) (37.86-56.14) (0.019-0.026) (1.933-3.528) (0.116-0.153) >200 (0.046-0.060) (0.480-1.121) (0.120-0.170) (0.299-0.415) (0.015-0.020) (13.68-46.83) (0.287-0.439) >200
S R S R
140 140 220 200
3.41 ± 0.62 1.44 ± 0.27 1.81 ± 0.49 2.22 ± 0.29
0.029 1.112 0.192 0.284
(0.024-0.034) (0.720-1.673) (0.090-0.348) (0.223-0.362)
S R S R
120 120 120 120
2.94 ± 0.57 3.39 ± 0.57 2.76 ± 0.47 3.28 ± 0.62
0.032 0.081 0.014 0.069
(0.026-0.040) (0.066-0.099) (0.011-0.018) (0.057-0.084)
S R S R
180 220 120 120
3.31
to an aza-
Resistance levelb
2,262 326 50 13 >391 >1,630 162 120 > 1,504 14 2.5 1,495 >559
38 1.5
Pyrethroids Fenvalerate Permethrin
2.5 5
Carbamates Propoxur Carbaryl
±
0.60
0.463 (0.390-0.542) >200 >100 >100
>432 >1
a R, resistant strain 594vb obtained by selecting the original colony with azamethiphos for four consecutive generations; S, susceptible strain CSMA. b Resistance level at LD50 compared with susceptible strain.
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Table 2. Toxicity or various organophosphate, organochlorine, methiphos-resistant and -susceptible strain or house flics Insecticide
Vol. 84, no. 6
ENTOMOLOGY
December 1991
SAITO ET AL.: RESISTANCE IN AZAMETHIPHOS-SELECTED
given in Table 2. The 594vb strain showed crossresistance to all the insecticides evaluated. However, resistance to dichlorovos, propetamphos, and prothiophos was relatively low. Similarly, the LD.os for the chlorinated hydrocarbon, pyrethroid, and carbamate insecticides are summarized in Table 2. The flies were highly resistant to propoxur and moderately resistant to -y-BHC. Resistance top,p'-DDT and the pyrethroid insecticides was low. Therefore, we conclude that the main factor responsible for resistance in the flies involves mechanisms other than AChE sensitivity and nerve sensitivity due to the gene knockdown resistance. Acknowledgment
References
Cited
Bliss, C. I. 1935. The calculation of the dosage-mortality curve. Ann. Appl. BioI. 22: 134-167. Brown, A.W.A. 1961. The challenge of insecticide resistance. Bull. Entomol. Soc. Am. 7: 6-19. Danish Pesl Infeslation Laboralory (DPIL). 1989. Danish Pest Infestation Laboratory Annual Report, 1988. DPIL, Lyngby, Denmark.
1637
Hama, H. & T. Iwata. 1971. Insensitive cholinesterase in the NaKagawara strain of the green leafhopper, Nephotettix cincticeps Uhler (Hemiptera: Cicadellidae), as a cause of resistance to carbamate insecticides. Appl. Entomol. Zool. 6(4): 183-191. Kasai, Y., T. Konno & W. C. Dauterman. 1992. Role of phosphorotriester hydrolases in the detoxication of organophosphorous insecticides, pp. 169-182. In J. E. Chambers & P. E. Levi [eds.], Organophosphates: chemistry fate and effects. Academic, New York. Miller, T. A., J. M. Kennedy & C. Collins. 1979. CNS insensitivity to pyrethroids in the resistant Kdr strain of house flies. Pestic. Biochem. Physiol. 12: 224-230. O'Brien, R. D. 1967. Insecticides action and metabolism. Academic, New York. Oppenoorth, F. J. & W. Welling. 1976. Biochemistry and physiology of resistance, pp. 507-551. In C. F. Wilkinson [ed.], Insecticide biochemistry and physiology. Plenum, New York. Smissaert, H. R. 1964. Cholinesterase inhibition in spider mites susceptible and resistant to organophosphate. Science 143: 129-131. Tsukamoto, M., T. Narahashi & T. Yamasaki. 1965. Genetic control of low nerve sensitivity to DDT in insecticide-resistant houseflies.Botyu-Kagaku 30: 128132. Received for publication 7 June 1991.
29 January 1991; accepted
Downloaded from http://jee.oxfordjournals.org/ by guest on June 9, 2016
This work was supported in part by the North Carolina Agricultural Research Service, Raleigh, and in part by Public Health Service Grant ES-00044 from the National Institute of Environmental Health Sciences.
HOUSE FLIES
J.
Econ. Entomol. 84(6): 1635-1637 (1991)
ABSTRACT A colony of azamethiphos-resistant house flies, Musca domestica (L.), was obtained from Denmark and further selected in the laboratory with azamethiphos for four generations. LD ••s for various insecticides were determined and compared with those of a susceptible house fly strain. The selected flies showed cross-resistance to all insecticides evaluated. The flies were highly resistant to most organophosphorus, carbamate, and chlorinated hydrocarbon insecticides except prothiophos, p,p'-DDT, and the pyrethroids. We conclude that the main mechanisms responsible for resistance are presumed to be factors other than acetylcholinesterase sensitivity and nerve sensitivity due to knockdown resistance. Insecta, cross resistance, azamethiphos, Musca domestica
AZAMETHIPHOS (S-6-chloro-2-oxo-oxazol[ 4,5b]pyridin-3-ylmethyl) O,O-dimethyl phosphorothioate is an insecticide under development by CIBA-GEIGY, Basel, Switzerland. It has shown good activity against adult house flies, Musca domestica (L.), when applied as a paint to cattle, pig, or poultry stalls or buildings, or when applied to the surface of mallure (DPIL 1989). The acute oral LDo".of azamethiphos is 1,180 mg/kg to the rat and 1,400 mg/kg to the mouse. Thus, the compound has a low acute toxicity to mammals. In 1987 and 1988, resistant flies were found on two farms in Denmark (DPIL 1989). The insecticide had been used as paint-on bait for fly control in 1985 and 1986. The development of DDT resistance in the house fly was first reported in 1946 (Brown 1961). Subsequently, organophosphorus resistance in the house fly and the Culex mosquito showed cross resistance to DDT (O'Brien 1967). A decrease in insecticide sensitivity to DDT and pyrethroids is due to the gene Kdr (Tsukamoto et al. 1965, Oppenoorth & ~elling 1976, Miller et al. 1979). Another mechanism responsible for organophosphate and carbamate resistance is a decrease in AChE sensitivity (Smissaert 1964, Rama & Iwata 1971). The purpose of our study was to investigate the resistance pattern of an azamethiphos-resistant strain of house flies after further selection with azamethiphos in the laboratory. Materials and Methods Insecticides. The insecticides used in this study, their purities, and their sources were as follows.
I Current address: Faculty of Horticulture, Chiba University, Matsudo, Matsudo-shi, Chiba-Ken 271, Japan.
Azamethiphos (99.0%) was supplied by CIBAGEIGY, Greensboro, N.C. Fenitrothion (97.0%), diazinon (98.5%), dichlorovos (98.0%), malathion (98.8%), trichlorfon (98.0%), ethion (99.0%), ph osdrin (98.0%), azinphosmethyl (99.0%), propetamphos (89.0%), fenvalerate (98.0%), permethrin (98.0%), and propoxur (99.0%) were obtained from Chern Service, West Chester, Pa. Prothiophos (94.5%) was provided by Nihon Tokushu Noyaku Seizo K.K., Tokyo, Japan. Carbaryl (99.0%) was provided by Union Carbide Corp., Research Triangle Park, N.C. Methyl parathion (98.0%) and p,p'-DDT (99.0%) were obtained from City Chemical Corp., New York. -y-BRC (97.0%) was obtained from Aldrich Chemical Company, Milwaukee, Wis. Fenitrooxon (95.0%) was prepared by reacting dimethyl phosphorochloridate with the sodium salt of 3-methyl-4-nitrophenol (Kasai et al. 1992). Insects. The azamethiphos-resistant 594vb strain (DPIL 1989) of the house fly was supplied by J. Keiding of the Danish Pest Infestation Laboratory, Lyngby, Denmark. Insecticide-susceptible flies of the CSMA strain were obtained from a culture originally supplied by Union Carbide Chemical Company in 1962 and maintained since then at North Carolina State University. The resistant and susceptible strains of house flies were maintained as adults on a diet of milk and sugar at 22-27°C. Selection with Azamethiphos. Selection of the 594vb colony was done by topical application of 0.5-~1 acetone solutions containing azamethiphos to 100 2-d-old female and male flies. Twenty-four hours after treatment, flies that had survived were transferred to a clean cage to mate and produce offspring. Azamethiphos was applied at the rate of 1 ~g per fly in the first generation, 10 ~g in the second generation, and 100 ~g in the third and fourth generations.
0022-0493/91/1635-1637$02.00/0
© 1991 Entomological Society of America
Downloaded from http://jee.oxfordjournals.org/ by guest on June 9, 2016
KEY WORDS
1636
JOURNAL
OF ECONOMIC
Table 1. Selection or 594vb house fly colony with azamethiphos and response or resulting population
Generation I 2 3 4
Azamethiphos applied, I'g/f1y
% Mortality
I 10 100 100
53 67 31 53
Toxicity Evaluations. The toxicity of the various insecticides was determined by topically applying 0.5 /-llof acetone solution of each insecticide to the dorsal surface of the thorax of adult female house flies (3- to 6-d old). At least 20 flies were treated
at each concentration; four to eight concentrations were tested. Control flies were treated with acetone only. The flies were kept at 22-27°C, and mortality was determined 24 h after the treatment. Paralyzed flies were considered dead. LD.os were estimated as described by Bliss (1935). Results and Discussion A summary of the selection of the 594vb colony with azamethiphos is given in Table 1. After the third and fourth generations, the LD50 was > 100 /-lgazamethiphos per fly. This is more than 100fold higher than the LD50 of the original 594vb colony. LDsos of the various organophosphorous insecticides to 594vb and the susceptible CSMA strain are
Organophosphates Azamethiphos Fenitrothion Diazinon
Dichlorvos Malathion Trichlorfon Ethion Phosdrin Azinphosmethyl Propetamphos Prothiophos Methyl parathion Fenitrooxon Organochlorines -y·BHC p,p'·DDT
House fly strainG
n
pyrethroid,
Slope ± SE
± ± ± ± ± ± ± ± ±
and carbamate
insecticides
LDso (95%CL), I'g/2
S R S R S R S R S R S R S R S R S R S R S R S R S R
700 300 120 160 180 180 180 120 160 220 280 140 180 220 120 200 140 140 120 120 100 120 160 120 260 200
4.50 6.85 4.02 2.24 3.93 2.79 4.23 3.63 4.36
0.57 1.54 0.74 0.37 0.74 0.40 0.70 0.66 0.75
0.058 131.2 0.062 20.21 0.062 3.108 0.009 0.116 0.512
3.52 ± 0.47
0.092
2.53 2.43 4.14 1.74 4.45
± 0.38 ± 0.45 ± 0.72 ± 0.26 ± 0.67
0.285 46.10 0.022 2.637 0.133
5.27 1.80 4.06 7.06 4.15 0.98 2.23
± 0.86 ± 0.41 ± 1.00 ± 2.25 ± 0.70 ± 0.26 ± 0.29
0.052 0.720 0.143 0.352 0.017 25.41 0.358
(0.053-0.064) (119.5-144.0) (0.053-0.073) (15.52-26.29) (0.054-0.071) (2.582-3.745) (0.008-0.011) (0.097-0.138) (0.446-0.588) >200 (0.082-0.105) >150 (0.226-0.355) (37.86-56.14) (0.019-0.026) (1.933-3.528) (0.116-0.153) >200 (0.046-0.060) (0.480-1.121) (0.120-0.170) (0.299-0.415) (0.015-0.020) (13.68-46.83) (0.287-0.439) >200
S R S R
140 140 220 200
3.41 ± 0.62 1.44 ± 0.27 1.81 ± 0.49 2.22 ± 0.29
0.029 1.112 0.192 0.284
(0.024-0.034) (0.720-1.673) (0.090-0.348) (0.223-0.362)
S R S R
120 120 120 120
2.94 ± 0.57 3.39 ± 0.57 2.76 ± 0.47 3.28 ± 0.62
0.032 0.081 0.014 0.069
(0.026-0.040) (0.066-0.099) (0.011-0.018) (0.057-0.084)
S R S R
180 220 120 120
3.31
to an aza-
Resistance levelb
2,262 326 50 13 >391 >1,630 162 120 > 1,504 14 2.5 1,495 >559
38 1.5
Pyrethroids Fenvalerate Permethrin
2.5 5
Carbamates Propoxur Carbaryl
±
0.60
0.463 (0.390-0.542) >200 >100 >100
>432 >1
a R, resistant strain 594vb obtained by selecting the original colony with azamethiphos for four consecutive generations; S, susceptible strain CSMA. b Resistance level at LD50 compared with susceptible strain.
Downloaded from http://jee.oxfordjournals.org/ by guest on June 9, 2016
Table 2. Toxicity or various organophosphate, organochlorine, methiphos-resistant and -susceptible strain or house flics Insecticide
Vol. 84, no. 6
ENTOMOLOGY
December 1991
SAITO ET AL.: RESISTANCE IN AZAMETHIPHOS-SELECTED
given in Table 2. The 594vb strain showed crossresistance to all the insecticides evaluated. However, resistance to dichlorovos, propetamphos, and prothiophos was relatively low. Similarly, the LD.os for the chlorinated hydrocarbon, pyrethroid, and carbamate insecticides are summarized in Table 2. The flies were highly resistant to propoxur and moderately resistant to -y-BHC. Resistance top,p'-DDT and the pyrethroid insecticides was low. Therefore, we conclude that the main factor responsible for resistance in the flies involves mechanisms other than AChE sensitivity and nerve sensitivity due to the gene knockdown resistance. Acknowledgment
References
Cited
Bliss, C. I. 1935. The calculation of the dosage-mortality curve. Ann. Appl. BioI. 22: 134-167. Brown, A.W.A. 1961. The challenge of insecticide resistance. Bull. Entomol. Soc. Am. 7: 6-19. Danish Pesl Infeslation Laboralory (DPIL). 1989. Danish Pest Infestation Laboratory Annual Report, 1988. DPIL, Lyngby, Denmark.
1637
Hama, H. & T. Iwata. 1971. Insensitive cholinesterase in the NaKagawara strain of the green leafhopper, Nephotettix cincticeps Uhler (Hemiptera: Cicadellidae), as a cause of resistance to carbamate insecticides. Appl. Entomol. Zool. 6(4): 183-191. Kasai, Y., T. Konno & W. C. Dauterman. 1992. Role of phosphorotriester hydrolases in the detoxication of organophosphorous insecticides, pp. 169-182. In J. E. Chambers & P. E. Levi [eds.], Organophosphates: chemistry fate and effects. Academic, New York. Miller, T. A., J. M. Kennedy & C. Collins. 1979. CNS insensitivity to pyrethroids in the resistant Kdr strain of house flies. Pestic. Biochem. Physiol. 12: 224-230. O'Brien, R. D. 1967. Insecticides action and metabolism. Academic, New York. Oppenoorth, F. J. & W. Welling. 1976. Biochemistry and physiology of resistance, pp. 507-551. In C. F. Wilkinson [ed.], Insecticide biochemistry and physiology. Plenum, New York. Smissaert, H. R. 1964. Cholinesterase inhibition in spider mites susceptible and resistant to organophosphate. Science 143: 129-131. Tsukamoto, M., T. Narahashi & T. Yamasaki. 1965. Genetic control of low nerve sensitivity to DDT in insecticide-resistant houseflies.Botyu-Kagaku 30: 128132. Received for publication 7 June 1991.
29 January 1991; accepted
Downloaded from http://jee.oxfordjournals.org/ by guest on June 9, 2016
This work was supported in part by the North Carolina Agricultural Research Service, Raleigh, and in part by Public Health Service Grant ES-00044 from the National Institute of Environmental Health Sciences.
HOUSE FLIES
