Microsoft Word - 4-Dr Hanafi Ready to go.doc Iranian J Arthropod-Borne Dis, (2008), 2(1): 21-27 M Shahi et al: Evaluation of Five Local Formulated … 21 Original Article Evaluation of Five Local Formulated Insecticides against German Cockroach (Blattella germanica L.) in Southern Iran M Shahi 1, *AA Hanafi-Bojd 2, H Vatandoost 2 1 School of Public Health, Hormozgan University of Medical Sciences, Bandar Abbas, Iran 2 Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran (Received 15 Apr 2007; accepted 27 Jul 2008) Abstract Background: The German cockroach, Blattella germanica L., is a serious household and public health pest worldwide. Control of this species has been very difficult to achieve. Toxicity of cypermethrin EC10%, deltamethrin EC5%, diazinon EC0.5%, lambda-cyhalothrin EC5% and Negon® (permethrin+propoxur oil liquid1%) commercial formulations were investigated against adult males of German cockroaches collected from four hospitals of Bandar Abbas City, southern Iran, during 2006. These insecticides have been used for cockroach control in this city. Methods: The tests were carried out only on males by the glass jar contact method recommended by the WHO. Results: Maximum mortality rates of 20, 35, 90, and 100% were obtained after one hour contact to label-recom- mended doses of cypermethrin, deltamethrin, lambad-cyhalothrin, diazinon and permethrin+propoxur insecticides, respectively. KT50 results were different from 5.68 min for permethrin+propoxur mixture to 240.37 min for cyper- methrin. German cockroach showed < 80 per cent mortality using three pyrethroid insecticides. Conclusion: It seems that the label-recommended concentrations of these insecticides were wrong and lower than WHO advised for cockroach control. For monitoring of resistance it is recommended to do more tests using the pure active ingredient of these insecticides. Keywords: German cockroach, Commercial insecticides, Resistance, Hospital, Iran Introduction According to World Health Organization report, cockroaches have been in existence for about 360 million years (Cochran 1982). These insects are important pests because they spread filth and ruin food, fabrics and book-bindings. They disgorge portions of their partially digested food at intervals and drop feces. They also discharge a nauseous secre- tion both from their mouths and from glands openings on the body which gives a long- lasting, offensive cockroach smell to areas or food visited by them. Cockroaches are not usually the most important cause of a dis- ease, but they may play a supplementary role in some allergic diseases as well as spread of some diseases like: diarrheal diseases, amebic dysentery, cholera, leprosy, plague, typhoid fever and viral diseases such as poliomyelitis. Therefore they might be important in trans- mission of nosocomial infections (Pai et al. 2004). The German cockroach, Blattella ger- manica (L.), is a serious household and pub- lic health pest worldwide. Control of this spe- cies has been very difficult to achieve. In order to keep it under control, different organochlo- rine and organophosphate insecticides have been used, as well as carbamate and pyrethroid compounds. Still this species has been devel- oping resistance to these compounds. At pre- *Corresponding author: A.A. Hanafi-Bojd, Tel: +98 21 88951393, E-mail: aahanafibojd@tums.ac.ir Iranian J Arthropod-Borne Dis, (2008), 2(1): 21-27 M Shahi et al: Evaluation of Five Local Formulated … 22 sent, resistance has become a substantial prob- lem that sometimes causes failure of control operations in many countries (Atkinson et al. 1991). Heavy infestations of cockroaches can be effectively managed by chemical control measures, followed by environmental manage- ment to deprive them of food and shelter. The German cockroach is resistant to different insecticides (Cochran 1995, Hanafi-Bojd and Sadaghiani 2001, Vatandoost and Mousavi 2001). The present study was conducted to de- termine the susceptibility levels of this spe- cies to insecticides currently being used in its control program in four hospitals of Ban- dar Abbas City, southern Iran. Materials and Methods Study area The investigation was carried out over a period of 10 months of 2006 at Bandar Abbas City, Hormozgan Province (25º 24' - 28º 57' N. and 52º 41'- 59º 15' E.), bordered by the Persian Gulf. This city is the main economic seaport of Iran. Cockroach strains This research was carried out in four train- ing hospitals of Hormozgan University of Medi- cal Sciences in Bandar Abbas City, called: Shahid Mohammadi, Shariati, Koodakan and Ebne-Sina. B. germanica specimens were col- lected from different parts of the hospitals. The collections were made by trapping and hand catch methods. Traps were made by glass bottles containing bread and butter. The upper internal edge of the bottles, were coated with a fine layer of butter to prevent the es- cape of cockroaches. These traps were exter- nally covered with dark paper. The samples were collected weekly and sent to the Ban- dar Abbas Training and Public Health Research Center. Cockroach colonies were reared in an insectary, maintained in big glass containers at 27±2° C and a relative humidity of 77±3%. They were fed with rabbit food, bread, soybean and water. Chemicals To determine the levels of resistance, five commercial formulations of insecticides were used: cypermethrin EC10% (PARTO-NAR, Co.), deltamethrin EC5% (PARTO-NAR Co.), diazinon EC0.5% (GIAH Co.), lambda-cy- halothrin EC5% (PARTO-NAR, Co.) and Negon® (Permethrin+Propoxur) oil liquid 1% (IRAN CHEMICAL PRODUCTION Co.). These insecticides formulated in Iran and are using for insect pests (such as cockroaches). Contact glass jar test Tests were conducted on adult males by WHO standard method (WHO 1970). The duration of contact was 1 h and then cock- roaches were transferred to holding cups. Re- sults of mortality were recorded after 24 h. Concentrations were prepared based on la- bel-recommended doses of each commercial insecticide. The label recommended concen- trations for pyrethriod insecticides were as follows: Deltamethrin 2.5% EC, 50 ml in 5 lit water; lambda-cyhalothrin 5% EC, 50-70 ml in 8 lit water; cypermethrin 10% EC, 50-70 ml in 5 lit water. Diazinon was EC 60% (that we pre- pared its 0.5% solution) and the Negon® oil liquid 1% was labeled “ready to use”. Therefore, we diluted the insecticides based on their label and then pipetted 1 ml of each solution into labeled glass jars (surface area= 180 cm2). The upper inside lip of the jars were smeared with a thin layer of butter to prevent the cockroach escape. The insecti- cides were deposited evenly in the inner jar surface by rolling the jar on a flat surface un- til all liquid solvent had evaporated. Ten adult males were introduced into the jar and knockdown of the cockroaches was recorded at 5 min intervals. Four replicates and one control were carried out for each strain using every insecticide. Data analysis Iranian J Arthropod-Borne Dis, (2008), 2(1): 21-27 M Shahi et al: Evaluation of Five Local Formulated … 23 Results from all replicates for each insec- ticide were pooled and subjected to probit analysis (Finney 1971). Results Results of mortality after 1 h contact to label-recommended dosages of cypermethrin, deltamethrin, lambda-cyhalothrin, diazinon and Negon® (permethrin+propoxur) are showed in Table 1. Although in the case of three pyre- throid insecticides the mortality rates of cock- roaches were lower than 91%, but two other insecticides (Diazinon and Negon®) caused 100% mortality. The highest mortality rates for deltamethrin, lambdacyhalothrin and cy- permethrin was 35, 90 and 20%, respectively. KT50 values of tested cockroaches in contact to the insecticides were varied from a minimum of 5.68 min for Negon® in the Ebne-Sina strain to a maximum of 240.37 min for cypermethrin in Koodakan strain, re- spectively (Table 2). KT50 levels of three py- rethroid insecticides: cypermethrin, lambda- cyhalothrin and deltamethrin were distinctly lower in Shahid Mohammadi strain. Table 1. Mortality results of one hour contact of male German cockroaches (Blattella germanica L.) to five com- mercial insecticides, Bandar Abbas, southern Iran, 2006 Cypermethrin Lambda-cyhalothrin Deltamethrin Diazinon Propoxur+PermethrinInsecticide Hospital No. % No. % No. % No. % No. % Shahid Mohammadi 2 5 36 90 14 35 40 100 40 100 Shariati 5 12.5 33 82.5 6 15 40 100 40 100 Ebne-Sina 8 20 22 55 7 17.5 40 100 40 100 Koodakan 3 7.5 16 40 9 22.5 40 100 40 100 Control 0 0 1 2.5 0 0 0 0 0 0 Table 2. KT50 (min) values of Blattella germanica from four hospitals of Bandar Abbas City, southern Iran, in contact to five commercial formulation of insecticides, 2006 Insecticide Hospital Cypermethrin Lmabda- cyhalothrin Deltamethrin Diazinion Propoxur+Permethrin Lower 47.72 18.41 31.66 44.05 7.75 KT50 53.78 20.99 35.49 46.79 9.89 Shahid Mohammadi Upper 63.70 23.57 40.22 50.23 11.89 Lower 81.64 32.61 59.68 33.89 5.36 KT50 118.67 35.29 71.49 35.27 7.22 Shariati Upper 441.97 38.17 109.87 36.65 8.76 Lower - 31.23 67.67 38.22 3.61 KT50 - 35.69 85.77 40.26 5.68 Ebne-Sina Upper - 41.45 135.29 42.17 7.44 Lower 113.66 43.39 53.86 32.68 11.95 KT50 240.37 55.52 69.26 34.94 14.02 Koodakan Upper 9292.93 90.62 103.61 37.27 15.91 Iranian J Arthropod-Borne Dis, (2008), 2(1): 21-27 M Shahi et al: Evaluation of Five Local Formulated … 24 Table 3. WHO label recommended concentrations against cockroaches for the studied insecticides Recommended concentration (%) Insecticide WHO Label Cypermethrin 0.05-0.2 0.0014 Deltamethrin 0.03-0.05 0.025 Lambda- cyhalothrin 0.015-0.03 0.004 Diazinon 0.5 0.5 Permethrin 0.25 1 Propoxur 1 1 Discussion Cockroaches are difficult to control with insecticides for several reasons, e.g. they may become resistant to commonly used com- pounds. Moreover, many insecticides are re- pellent to them and are therefore avoided (Wooster and Ross 1989). Chemical control gives only temporary relief and, wherever possible, it should be accompanied by envi- ronmental sanitation and house improvement (Schal 1988). In this study, German cockroaches showed less than 80% mortality using cypermethrin, deltamethrin and lambdacyhalothrin (except for two strains) (Table1). An investigation on ef- ficacy of synthetic pyrethroids (0.02% del- tamethrin+0.13% allethrin) and propoxur aero- sol in the control of German cockroach in India showed that 89.36-87.8 and 77.95- 59.74% reductions were achieved with pro- poxur and synthetic pyrethroid treatment re- spectively by first week post-treatment (Agrawal et al. 2005). Results of another study on German cockroaches using commercial insec- ticides in north of Iran showed 100% mortal- ity after 1h contact with propoxur 0.32%, permethrin 0.32%, bendiocarb 0.24% and pirimiphos methyl 0.16% (Haghi et al. 1997). The resistance levels of 12 strains of Ger- man cockroach in Peninsular Malaysia were low to high (2.8 to 92x) for carbamates (pro- poxur and bendiocarb), low (2.0 to 7.6x) for organophosphate (chlorpyrifos) and low to moderate (1.0 to 23x) for pyrethroids (cyper- methrin and permethrin) when compared to a susceptible strain (Lee et al. 1996). Such lev- els were observed in our study and we found diazinon and permethrin+propoxur based in- secticides very effective, rather than the other tested insecticides. WHO introduced the insecticides and their concentrations for con- trol of cockroaches (Chavasse and Yap 1997, Rozendaal 1997). Table 3 shows the WHO recommended concentrations of insecticides that are used in this study in comparing with the label recommended dose of them for cockroaches control. It can be observed that some commercial insecticides advised very lower concentrations of active ingredient than WHO recommendation that may be the cause of low mortality in our tests. So for re- sistance monitoring of German cockroaches in the studied hospitals of Bandar Abbas, it is recommended to test the active ingredient of tested insecticides based on WHO concen- trations. Study of susceptibility level of German cockroach to lambda-cyhalothrin in Tehran, the capital city of Iran, showed 4 out of 5 strains of this species are tolerant and only one is susceptible (Ladonni 1997). The ir- regular use of insecticides, especially pyre- throids, in the insect pests control programs, is resulted to increase their tolerance or re- sistance levels. For a successful control pro- gram against German cockroach in these hos- pitals, it is recommended to use correct con- centrations of effective insecticides from dif- ferent groups. Application method and accu- racy in spraying with due attention to cock- roach shelters, are another factors for success. In the study of permethrin resistance ratio (RR) by tarsal contact tests on first-instar nymphs of B. germanica, KT50 of 8.41 min and LT50 of 12.82 with permethrin 15 mg/m2 were ob- tained and all wild strains showed significant levels of resistance to permethrin, with RR Iranian J Arthropod-Borne Dis, (2008), 2(1): 21-27 M Shahi et al: Evaluation of Five Local Formulated … 25 of 17-27 fold at the KT50 level (Ladonni 2000). Our minimum of KT50 that observed in mixed insecticide that contains propoxur+ permethrin 1% was ranged from 5.68 to 14.02 min (Table 2). The susceptibility level of eleven strains of germen cockroach was evaluated against permethrin and fipronil by topical application. In all strains, cockroaches showed different degrees of resistance to permethrin (Nassirian et al. 2006). We ob- served 100% mortality using Negon® that contains permethrin, but it is a mixture of py- rethroid and carbamate insecticides. This mix- ture destroys all resistance mechanisms and if there was a compound of only permethrin, we could make a better inference about the resistance status of B. germenica strains of Bandar Abbas. First nymphal stages of differ- ent strains of B. germanica were tested to diazinon 2% using insecticide impregnated pa- pers in Tehran City, Iran (Ladonni et al. 1997). Comparison of LT50 of field strain with the susceptible insectary strain showed 3 of them had tolerance (1.5< RR< 2.5). Our study showed 100% susceptibility to the WHO recommended dose of diazinon. Insec- ticide resistance studies on B. germanica from Cuba showed evidence of resistance to cyper- methrin, deltamethrin and lambda-cyhalothrin (Diaz Pantoja et al. 2000). The resistance to six insecticides was in- vestigated on field strains of German cock- roaches caught in hospitals from various parts of Poland. The tested field strains showed high or moderate resistance to permethrin, del- tamethrin, cypermethrin and bendiocarb, mod- erate resistance or tolerance to etofenproks, and tolerance or susceptibility to propoxur (Gliniewicz et al. 1996). Although we found different rates of mortality for these pyre- throids ranging from 7.5 to 90% (Table 1), it may be partly due to incorrect concentrations advised by their manufacturing company. To determine the resistances in cohorts of B. germanica from hospitals and households of Thailand to organophosphates, carbamates and pyrethroids, bioassays by topical appli- cation were carried out. Resistance ratio (RR) was determined by comparing the LD50 of the collected cohorts with that of a susceptible cohort. RR ranges of chlorpyrifos, propoxur and cypermethrin in the hospitals were 2.04- 28.80, 2.86-30.86 and 1.95-14.05 and those in the household were 1.92-17.72, 6.93-62.50 and 2.80-27.35, respectively. Significant cor- relations among the RRs of the three insecti- cides were separately found in the hospitals and households, indicating the existence of cross resistance among the three groups of insecticides (Pai et al. 2005). The history of cockroach control spray- ing in our studied hospitals showed that car- bamate and pyrethroids were mainly used such as: propoxur, cyfluthrin, deltamethrin and lambd-cyhalothrin. Inappropriate use of these insecticides can end to tolerance/resistance in cockroaches. Therefore, we suggest the label recommended concentration of cypermethrin, deltamethrin and lambda- cyhalothrin com- mercially insecticides that we used in this study have to change based on the WHO suggested concentrations to obtain best re- sults in cockroach control program of Bandar Abbas hospitals. Acknowledgements The authors are grateful to staff of Bandar Abbas Training and Public Health Research Center, especially Mr H Javdan, for their close collaboration. This project is financially sup- ported by Hormozgan University of Medical Sciences, Bandar Abbas, Iran. References Agrawal VK, Talik R, Dutta Gupta KK (2005) Efficacy of synthetic pyrethroid and propoxur aerosol in the control of German cockroaches (Dictyoptera: Blatel- lidae) in cookhouses. J Vect Borne Dis. 42: 117-121. Iranian J Arthropod-Borne Dis, (2008), 2(1): 21-27 M Shahi et al: Evaluation of Five Local Formulated … 26 Atkinson TH, Wadlergh RH, Koehler PG, Patteson R (1991) Pyrethroid resistance and synergism in a field strain of the German cockroach (Dictyoptera: Blat- tellidae). J Econ Entomol. 84(4): 1247– 1250. Chavasse DC, Yap HH (1997) Chemical Methods for the Control of Vectors and Pests of Public Health Importance, WHO/ CTD/ WHOPES/97.2. 129 pp. Cochran DG (1982) Cockroaches. Their biology, distribution and control. Docu- ment WHO/CDS/CPC/World Health Or- ganization Technical report. 82. 856. Ge- neva: WHO, pp 1-53. Cochran DG (1995) Insecticide resistance, in Understanding and Controlling the Ger- man cockroach, ed. by Rust MK, Owens JW and Reierson DA. Oxford University Press, New York, NY. pp.171-192. Diaz Pantoja C, Perez MG, Calvo E, Rodri- guez MM, Bisset JA (2000) Insecticide resistance studies on Blattella germanica (Dictyoptera: Blattellidæ) from Cuba. An- nals of New York Academy of Sci- ences. 916 (1): 628-634. Finney DJ (1971) Probit analysis. Third edi- tion. London, Cambridge University Press. Gliniewicz A, Krzeminska A, Sawicka B (1996) Susceptibility of cockroaches Blat- tella germanica L. collected from hos- pitals to selected pyrethroid and car- bamate insecticides. Rocz Panstw Zakl Hig. 47(3): 333-41. Haghi F, Gholami Sh, Sedaghat MM (1997) Determining of susceptibility level of hospital cockroaches of Sari to insecti- cides in 1996. Iranian Journal of Ma- zandaran University of Medical Sciences. 16: 1-6. Hanafi-Bojd AA, Sadaghiani Sh (2001) Cock- roaches of Iran. Tehran University of Medical Sciences Press, Tehran, Iran. Ladonni H (1997) Susceptibility of different field strains of Blattella germanica (Orthoptera: Blattellidae) to four pyre- throids. Iranian J Publ Health. 26(3-4): 35-40. Ladonni H (2000) Permethrin resistance ra- tios compared by two methods of test- ing nymphs of the German cockroach, Blattella germanica. Med Vet Ento- mol. 14: 213-216. Ladonni H, Abolhassani M, Shayeghi M (1997) Susceptibility of first nymphal stage of different strains of Blattella germanica L. (Dictyoptera: Blattellidae) to Diazinon and Propoxur, using insec- ticide impregnated paper. J Entomol Soc Iran. 17: 31-39. Lee CY, Yap HH, Chong NL (1996) Insecti- cide resistance and synergism in field collected German cockroaches (Dic- tyoptera: Blattellidae) in Peninsular Ma- laysia. Bulletin of Entomological Re- search. 86: 675-682. Nassirian H, Ladonni H, Shayeghi M, Vatan- doost H, Yaghoobi-Ershadi MR, Rassi Y, Abolhassani M, Abaei MR (2006) Comparison of permethrin and fipronil toxicity against German cockroach (Dic- tyoptera: Blattellidae) strains. Iranian J Publ Health. 35(1): 63-67. Pai HH, Chen WC, Peng CF (2004) Cock- roaches as potential vectors of nosoco- mial infections. Infect Control Hosp Epi- demiol. 25(11): 979-84. Pai HH, Wu SC, Hsu EL (2005) Insecticide resistance in German cockroaches (Blat- tella germanica) from hospitals and households in Taiwan. Int J Environ Health Res. 15(1): 33-40. Rozendaal JA (1997) Vector control. World Health Organization, Geneva. pp. 425. Schal G (1988) Relation among efficacy of insecticides, resistance levels, and sani- tation in the control of the German cockroach (Dictyoptera: Blattellidae). J Econ Entomol. 81: 536-544. Vatandoost H, Mousavi B (2001) Cock- roaches, their biology, distribution and Iranian J Arthropod-Borne Dis, (2008), 2(1): 21-27 M Shahi et al: Evaluation of Five Local Formulated … 27 control. (Ed by: Cochran DG). Tehran University Press, Tehran, Iran. WHO (1970) Tentative instructions for de- termining the susceptibility or resistance of cockroaches to insecticides. Techni- cal Report Series No. 443, World Health Organization, Geneva. Annex 12. pp. 130-133. Wooster MT, Ross MH (1989) Sublethal re- sponses of the German cockroach to vapors of commercial pesticides formula- tions. Entomol Exper Appl. 52: 49-55.