SEARCH

SEARCH BY CITATION

Keywords:

  • House fly;
  • Musca domestica L.;
  • imidacloprid;
  • methomyl;
  • knockdown;
  • insecticide resistance

ABSTRACT:

  1. Top of page
  2. ABSTRACT:
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES CITED

In this study, the knockdown and mortality effects of imidacloprid and methomyl were investigated. The residual surface applications were carried out to determine the knockdown effects (KDt50 and KDt95) and mortality (LD50 and LD95) induced by each insecticide. For mortality comparisons, the susceptible house fly (Musca domestica L., Diptera: Muscidae) of a WHO population and three natural field-collected M. domestica populations from Turkey were used. In conclusion, it was found that the resistance to imidacloprid and methomyl was significantly higher in the field populations when compared to the susceptible population from WHO. The results showed that applicators and pest management decision-makers should control and conduct an integrated pest management strategy by including biological agents to prevent the development of high levels of resistance in the field populations.


INTRODUCTION

  1. Top of page
  2. ABSTRACT:
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES CITED

The house fly, Musca domestica L. (Diptera: Muscidae), is a common pest of human and domestic animals and is also a vector of both human and animal diseases. The house fly is a mechanical carrier of more than 65 human and animal intestinal diseases and it is responsible for protozoan, bacterial, helminthic viral and rickettsial infections (Greenberg 1971, Sasaki et al. 2000, Shono and Scott 2003, Förster et al. 2007, Malik et al. 2007). The house fly is also a reliable indicator of the resistance status that could develop later in other insect pests. The use of insecticides is common for controlling pest populations. However, the development of resistance and cross-resistance among widely used and newly applied insecticides could affect the development of new strategies in integrated pest management. The resistance development in house flies has been observed worldwide (Keiding 1999, Kaufman et al. 2001, White et al. 2007, Acevedo et al. 2009).

Imidacloprid (IMI), a well-known pesticide of the neonicotinoid insecticide family, is a relatively new insecticide that may be of value in the control of house flies in Turkey. The neonicotinoid IMI has been registered since 1991 as a systemic insecticide applied on the soil, seed, and foliage for the control of sucking insects (Tomlin 1994). However, in 1994 the first case of IMI resistance in Bemisia tabaci Genn. was recorded (Elbert and Nauen 2000). In addition to IMI, the carbamates, organophosphates, and synthetic pyrethroid groups have been commonly used worldwide. The carbamate methomyl was first introduced in 1966 and it has been widely used to control pest populations in agricultural locations since the late 1970s (Butler et al. 2007). Methomyl resistance in house flies has been reported in many countries, including the U.S.A., Hungary, Denmark, Canada, Columbia, and Japan (Pap and Farkas 1994, Keiding 1999, Scott et al. 2000, Kristensen et al. 2001).

The assessment of the resistance status of M. domestica is necessary before an effective pest control program can be planned and implemented. This study was undertaken using three field-collected house fly populations from Turkey and compared with a reference, susceptible WHO population for level of resistance by using bioassays for the widely used pesticides IMI and methomyl. The bioassays were carried out by using the contact method since it provides reliable data and can be extrapolated to soil applications. The results of all populations were compared and the effectiveness of application method was evaluated.

IMI and methomyl formulations have been widely used as residual applications rather than fly bait formulations for almost five years in Turkey due to the higher costs of bait formulations. To the best of our knowledge, there are no reports in the open literature on insecticide resistance to IMI and methomyl in Turkish M. domestica populations. Therefore, the major aim of the present study was to determine the resistance status of M. domestica populations collected from three locations in Turkey (Ankara, Antalya, and Izmir). In this respect, the present study is expected to have a significant contribution to the difficult task of elaboration of effective and successful insecticide resistance management strategies to overcome resistance problems in field populations.

MATERIALS AND METHODS

  1. Top of page
  2. ABSTRACT:
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES CITED

Insects and insecticides

House flies were collected from three garbage dumps from August to the end of September, 2008 by sweep netting in livestock units in different cities of Turkey (Ankara, Antalya, Izmir). The populations were reared at 25 ± 1° C and 60% relative humidity with a 12:12 photoperiod in the Hacettepe University Insecticide Test and Production Laboratory. Four-to-seven-day-old female adult insects were used in this study. The reference WHO susceptible Musca domestica L. (Diptera: Muscidae) strain was used as the standard laboratory strain to which all field populations were compared (Kaufman et al. 2001). Technical grade imidacloprid (CAS No: 105827–78–9) and methomyl (CAS No: 16752–77-5) were used in the bioassay experiments. The insecticides were diluted in analytical grade acetone (Merck, Germany). Before each bioassay, test house flies were anesthetized using carbon dioxide (HABAS, Turkey) and placed into containers.

Bioassays

The knockdown time and the lethal doses of IMI and methomyl affecting 50% of the house fly individuals (KDt50) and (LD50) were evaluated using the residual contact method. Twenty female house flies were placed on a 400 cm2 tile surface treated with technical grade insecticide prior to the bioassay. The treatment doses were 5, 15, 50, 150, and 450 mg/m2 of IMI and methomyl. The tile surface was covered with a glass cone. In order to determine knockdown times, the flies were examined at 5, 10, and 15 min and affected flies recorded. After 15 min, the house flies were placed in untreated jars containing a 10% sugar-water solution. After 24 h, the number of affected flies was recorded. The criterion for mortality was insects without any movement (ataxic). The experiments consisted of three doses and were replicated three times. Afterwards, bioassay data were pooled. The KDt50 of 15 min and the lethal dose of 24 h (LD50) were calculated by Finney's Probit analysis (Finney 1962). Resistance factors (RF) were calculated by using the formula (LD50 of natural population/LD50 of susceptible), in comparison to the reference strain WHO.

RESULTS

  1. Top of page
  2. ABSTRACT:
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES CITED

The knockdown and mortality effects of the widely used insecticides imidacloprid (IMI) and methomyl were determined for house flies collected from Ankara, Antalya, and Izmir provinces of Turkey by using appropriate bioassay techniques. The results of the knockdown effects of IMI and methomyl in M. domestica populations are presented in Table 1. In methomyl bioassays in the Ankara population, the knockdown times (KDt50) were 14.93, 10.51, 8.43, 8.74, and 8.33 min; in the Antalya population, the KDt50 values were 9.41, 5.97, 5.47, 6.01, and 3.65 min; in the Izmir population, the KDt50 values were 80.48, 16.53, 12.29, 12.07, and 9.92 min; in the reference WHO population, the KDt50 values were 7.17, 5.03, 3.99, 2.67, and 2.47 min at 5, 15, 50, 150 and 450 mg/m2doses (Table 1).

Table 1.  The knockdown times of methomyl and imidacloprid (IMI) after 15 min insecticide exposure.
  MethomylImidacloprid
  Knockdown Effect (min)Knockdown Effect (min)
PopulationDose (mg/m2)nKDt50 (95 % CL)KDt95 (95% CL)Slope (SE)nKDt50 (95 % CL)KDt95 (95% CL)Slope (SE)
  1. * The value is > 10,000.

Ankara511414.39 (12.26–18.56)74.04 (44.123–204.416)2.31 (0.39)102119.02 (35.194- *)3888.72 (222.28-*)1.086 (0.505)
 1511110.51 (9.176–12.34)51.68 (33.957–112.85)2.37 (0.37)10634.88 (21.176–196.55)438.48 (108.77-*)1.496 (0.437)
 501038.43 (7.782–9.078)17.45 (15.453–20.582)5.204 (0.47)11416.41 (13.638–22.689)88.28 (49.437–289.491)2.25 (0.401)
 150978.74 (8.091–9.409)17.26 (15.363–20.244)5.568 (0.52)10713.25 (-)64.23 (-)0.00
 4501098.33 (7.731–8.930)16.48 (14.77–19.061)5.55 (0.484)1107.46 (6.492–8.364)27.2 (21.153–40.945)2.926 (0.382)
Antalya5929.41 (8.28–10.715)34.39 (25.273–58.702)2.992 (0.421)44622738.13 (-)*0.777 (0.792)
 15885.97 (4.764–6.947)23.8 (18.089–39.005)2.738 (0.432)385185.36 (62.87–15181.2)2225.69 (563.4 - *)1.52 (0.473)
 50925.48 (4.654–6.172)14.63 (12.428–18.777)3.854 (0.489)8649.45 (25.8–1256.6)369.6 (87.3 - *)1.88 (0.65)
 150986.01 (5.369–6.595)13.52 (11.847–16.314)4.670 (0.502)18220.74 (16.38–32.41)182.84 (84.537–899.48)1.74 (0.311)
 4501073.65 (2.500–4.517)13.49 (11.117–18.829)2.897 (0.478)10012.53 (10.91–15.21)53.92 (35.26–119.81)2.59 (0.41)
Izmir58780.48 (29.52-)1786.34 (-)1.221 (0.537)10653.75 (27.221–1093.826)615.14 (122.381-*)1.55 (0.509)
 158216.53 (13.896–22.48)60.65 (37.59–164.068)2.913 (0.533)36979.08 (41.65–504.9)460.39 (136.6–16044.67)2.15 (0.539)
 509812.29 (10.0–17.447)119.21 (52.7–1037.51)1.66 (0.389)9516.01 (12.729–25.798)126.15 (56.352–991.48)1.83 (0.415)
 1509212.07 (9.867–16.81)104.99 (48.64–778.43)1.75 (0.403)20020.62 (17.28–27.49)95.08 (59.48–227.73)2.44 (0.342)
 450969.92 (8.787–11.301)35.79 (26.305–60.707)2.95 (0.416)1375.84 (4.882–6.641)23.9 (18.908–34.823)2.68 (0.34)
WHO5647.17 (5.753–8.423)28.90 (20.507–57.758)2.717 (0.496)416186.61 (68.8–4133.84)3963.24 (520.05- *)1.239 (0.327)
 15695.03 (3.888–5.913)15.28 (12.415–21.970)3.407 (0.55)39519.29 (-)77.2 (-)2.731 (0.98)
 50803.99 (-)18.65 (-)2.458 (1.133)737.77 (6.596–8.911)27.41 (20.504–46.306)3.00 (0.47)
 150752.67 (1.027–3.840)11.48 (9.084–19.096)2.593 (0.632)1606.99 (6.387–7.572)28.52 (23.47–37.419)3.81 (0.339)
 450882.47 (0.956–3.593)10.73 (8.632–16.693)2.580 (0.609)713.20 (1.719–4.224)10.77 (8.767–16.144)3.124 (0.68)

In IMI bioassays in the Ankara population, the knockdown times (KDt50) were 119.02, 34.88, 16.41, 13.25, and 7.46 min; in the Antalya population, the KDt50 values were 22738.13, 185.36, 49.45, 20.74, and 12.53 min; in the Izmir population, the KDt50 values were 53.75, 79.08, 16.01, 20.63, and 5.84 min; in the reference WHO population, the KDt50 values were 186.61, 19.29, 7.78, 6.99, and 3.20 min at 5, 15, 50, 150, and 450 mg/m2doses (Table 1).

The lethal doses (LD50) of methomyl were determined in the Ankara, Antalya, Izmir, and WHO populations to be 11.05, 0.05, 4.01, and 0.18, respectively. The IMI LD50 was found to be higher than 10,000 in the Ankara and Antalya populations. The LD50 for the Izmir and WHO populations was 4,395.72 and 9.79, respectively (Table 2).

Table 2.  24-h lethal doses (LD50, mg/m2) of methomyl and imidacloprid (IMI) in house flies.
   Methomyl   
PopulationnLD50(95% CL)LD95(95% CL)Slope (SE)X2RF
Ankara53411.05 (0.593–31.527)593.53 (136.95–556307.7)0.95 (0.20)13.560.40
Antalya4770.05 (0.0–0.564)773.41 (208.695–40980.652)0.391 (0.109)1.670.27
Izmir4554.01 (0.0–17.487)484.70 (91.242-)0.79 (0.223)12.41321.94
WHO3760.18 (0.001–1.041)26.78 (12.396–77.775)0.759 (0.210)7.4021
   Imidacloprid   
PopulationnLD50(95% CL)LD95(95% CL)Slope (SE)X2RF
  1. * The value is >10,000. SE: Standard error of the mean, RF: Resistance factor.

Ankara539**0.32 (0.17)2.871-
Antalya1199**0.11 (0.235)7.361-
Izmir9074395.72 (-)*0.28 (0.234)7.587449.05
WHO11159.79 (-)1302.910.77 (0.250)6.9851

The resistance factors (RF) were calculated by using the LD50 data. The RF values of methomyl were calculated as 60.40, 0.27, and 21.94 in the Ankara, Antalya and Izmir populations, respectively. The RF value of IMI was 449.05 for the Izmir population. The RF values of IMI for the Ankara and Antalya populations were too high to be calculated (Table 2).

DISCUSSION

  1. Top of page
  2. ABSTRACT:
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES CITED

In this study, knockdown and mortality effects of two insecticides; imidacloprid (IMI) and methomyl, were determined in house flies collected from three garbage dumps from locations in Ankara, Antalya, and Izmir in Turkey. The knockdown time (KDt50) was decreased with increasing methomyl doses in Ankara, Antalya, Izmir, and the WHO susceptible populations. The KDt50 of the Izmir population was 80 min with a dose of 5 mg/m2. Knockdown time was reduced with increasing methomyl doses. In methomyl bioassays, it was clearly seen that the most resistant population was from Izmir, followed by Ankara, Antalya, and WHO populations, respectively.

Similarly, the knockdown times (KDt50) decreased with increasing IMI doses in the Ankara, Antalya, Izmir, and WHO populations. In contrast, the KDt50 of the 5 mg/m2 dose was shorter than that of the 15 mg/m2 dose in the Izmir population. This result may be due to differences in the number of individuals used at each dose. Moreover, the KDt50 of Antalya was 22,738.13 min at the 5 mg/m2 dose. This value is 122-fold higher than that of the WHO population. Besides, the KDt95 of Antalya population was four-fold higher than that of the WHO population. It is clearly seen that the most resistant population was from Antalya; the others were the Ankara, Izmir, and WHO populations, respectively, in the IMI bioassays (Table 1).

The lethal doses (LD50) of methomyl calculated from the results of the 24-h residual contact method were found to be higher than that of IMI (Table 2). The LD50 of methomyl in the Ankara population was 11.05 and therefore, this population was 60-fold more resistant than the susceptible WHO population. Besides, the LD50 level of Izmir population was found to be 4.01 and therefore 20-fold more resistant than the WHO population. The mortality based on LD50 values of IMI were found to be higher than 10,000 in the Ankara and Antalya populations. In the Izmir population, the LD50 of IMI was 4,395.72 and the resistance factor (RF) was 449.05. It is clear that resistance to IMI was significantly higher in the natural field populations of Turkey. The contrary was expected, since methomyl is more toxic than IMI. The 24-h LD50 for methomyl ranged from 0.27 to 60.40 mg/m2 in the field populations.

In Turkey, resistance has been reported for a number of insecticides in house flies (Sisli et al. 1983, Kence and Kence 1985, Caglar 1991, Caglar et al. 2000, Yamanel and Cakir 2004, Akiner and Caglar 2006). The occurence of insecticide resistance in house flies depends on the insecticide used, duration of exposure, and frequency of application (WHO 1991). Therefore, effective insecticide management strategies and their implementation are necessary for the prevention of rapid resistance development. Some examples of strategies employed against resistance development in house flies are restriction of chemical use, application of mixtures containing more than one insecticide, and rotation of several chemicals (Kaufman et al. 2001). In addition, Srinivasan and Amalraj (2003) recommended introduction of biological control by using parasitic wasps and insect growth regulators in combination for controlling the development of house fly resistance. Moreover, an integrated approach involving biological, chemical, and other environmental tools could help to control the pest populations better since there would be fewer possibilities for the development of resistance. The wider aim is to conserve biological/natural resources and the ecological balance at the same time (Malik et al. 2007).

In this study, the resistance to IMI and methomyl were found to be significantly high in house fly field populations in Turkey. Therefore, their application should be used cautiously. In addition, replacement of the first insecticide used with alternate insecticides in following applications could prevent resistance development and contribute to successful pest management. Hopefully, this would help improve resistance management strategies while conserving the environment.

REFERENCES CITED

  1. Top of page
  2. ABSTRACT:
  3. INTRODUCTION
  4. MATERIALS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES CITED
  • Acevedo, G.R., M. Zapater, and A.C. Toloza. 2009. Insecticide resistance of house fly, Musca domestica (L.) from Argentina. Parasitol. Res. 105: 489493.
  • Akiner, M.M. and S.S. Caglar. 2006. The status and seasonal changes of organophosphate and pyrethroid resistance in Turkish populations of the house fly, Musca domestica L. (Diptera: Muscidae). J. Vector. Ecol. 31: 426432.
  • Butler, S.M., A.C. Gerry, and B.A. Mullens. 2007. House fly (Diptera: Muscidae) activity near baits containing (Z)-9-tricosene and efficacy of commercial toxic fly baits on a Southern California dairy. J. Econ. Entomol. 100: 14891495.
  • Caglar, S.S. 1991. The investigation on resistance level to tetramethrin of house fly, Musca domestica L. (Diptera: Muscidae) and life table studies. Tr. J. Zool. 15: 9197.
  • Caglar, S.S., M.M. Akiner, and N. Yazgan. 2000. Resistance to organochlorine and pyrethroid insecticides in different populations of Musca domestica L. (Diptera: Muscidae). Paper presented at 13th European Society for Vector Ecology Meeting, 24–29 September, Antalya, Turkey.
  • Elbert, A. and R. Nauen. 2000. Resistance of Bemisia tabaci (Homoptera: Aleyrodidae) to insecticides in southern Spain with special reference to neonicotinoids. Pest. Manag. Sci. 56: 6064.
  • Greenberg, B. 1971. Flies and Disease, Vol I. Princeton University Press, Princeton , NJ , 856 pp.
  • Finney, D.J. 1962. Probit Analysis. Cambridge University Press, 318 pp.
  • Förster, M., S. Klimpel, H. Mehlhorn, K. Sievert, S. Messler, and K. Pfeffer. 2007. Pilot studies on synantropic flies (e.g. Musca, Sarcophaga, Calliphora, Fania, Lucilia, Stomoxys) as vectors of pathogenic microorganisms. Parasitol. Res. 101: 243246.
  • Kaufman, P.E., J.G. Scott, and D.A. Rutz. 2001. Monitoring insecticide resistance in house flies (Diptera: Muscidae) from New York dairies. Pest. Manag. Sci. 57: 514521.
  • Keiding, J. 1999. Review of the global status and recent development of insecticide resistance in field populations of the house fly Musca domestica (Diptera: Muscidae). Bull. Entomol. Res. 89: 767.
  • Kence, A. and M. Kence. 1985. Malathion resistance in house fly populations distributed in Turkey. Doga Bilim Derg. Seri A2, 9: 565573.
  • Kristensen, M., A.G. Spencer, and J.B. Jesperson. 2001. The status and development of insecticide resistance in Danish populations of the house fly Musca domestica L. Pest Manag. Sci. 57: 8289.
  • Malik, A., N. Singh, and S. Satya. 2007. House fly (Musca domestica): a review of control strategies for a challenging pest. J. Environ. Sci. Hlth. Part B 42: 453469.
  • Pap, L. and R. Farkas. 1994. Monitoring of resistance of insecticides in house fly (Musca domestica) populations in Hungary. Pestic. Sci. 40: 245258.
  • Sasaki, T., M. Kobayashi, and N. Agui. 2000. Epidemiological potential of excretion and regurgitation by Musca domestica (Diptera: Muscidae) in the dissemination of Escherichia coli O157: H7 to food. J. Med. Entomol. 37: 945.
  • Scott, J.G., T.G. Alefantis, P.E. Kaufman, and D.A. Rutz. 2000. Insecticide resistance in house flies from caged-layer poultry facilities. Pest Manag. Sci. 56: 147153.
  • Shono, T. and J.G. Scott. 2003. Spinosad resistance in the house fly, Musca domestica, is due to a recessive factor on autosome 1. Pestic. Biochem. Physiol. 75: 17.
  • Srinivasan, R. and D.D. Amalraj. 2003. Efficacy of insect parasitoid Dirhinus himalayanus (Hymenoptera: Chalcididae) and insect growth regulator, triflumuron against house fly, Musca domestica (Diptera: Muscidae). Indian J. Med. Res. 118: 158166.
  • Sisli, M.N., A. Bosgelmez, O. Kocak, and H. Porsuk. 1983. The effect of malathion, fenitrothion and propoxur on the house fly, Musca domestica L. (Diptera: Muscidae) populations. Mikrobiyol. Bult. 17: 4962.
  • Tomlin, C. 1994. The Pesticide Manual (A World Compendium). 10th edition. The British Crop Protection Council and The Royal Society of Chemistry. Cambridge , England . pp. 591593.
  • White, W.H., C.M. McCoy, J.A. Meyer, J.R. Winkle, P.R. Plummer, C.J. Kemper, R. Starkey, and D.E. Snyder. 2007. Knockdown and mortality comparisons among spinosad-, imidacloprid-, and methomyl-containing baits against susceptible Musca domestica (Diptera: Muscidae) under laboratory conditions. J. Econ. Entomol. 100: 155163.
  • World Health Organization. 1991. Vector Control Series. The house fly training and information guide, intermediate level. WHO/VBC/90.987 Geneva, Switzerland.
  • Yamanel, S. and S. Cakir. 2004. Insecticide resistance in some Turkish house fly (Musca domestica L.) populations to methyl-parathion and diazinon from the organophosphate insecticides. Turk. Parazit. Derg. 28: 210214.