41 J Health Sci Surveillance Sys July 2013; Vol 1; No 1 Carbamate Insecticides Resistance Monitoring of Adult Male German Cockroaches, Blattella germanica (L.), in Southern Iran Mohammad Djaefar Moemenbellah-Fard 1 , Mohammad Reza Fakoorziba 1 , Kourosh Azizi 1 , Mohsen Mohebbi-Nodezh 2 Introduction The German cockroach, Blattella germanica L. (Dictyoptera: Blattellidae), is by far the most important indoor domestic pest in Iran. It is a major synanthropic insect in houses, hospitals and residential areas. 1, 2 It has been recognized as a pressing public health problem due to its potential to carry, disseminate and transmit human disease- causing pathogens as well as induction of asthma. 3 It is a small, highly proliferative, flightless and pestiferous vector which necessitates its control. 4 Insecticide resistance poses an increasing problem to current pest control efforts. 5 By 1 Department of Medical Entomology, Research Center for Health Sciences, School of Health and Nutrition, Shiraz University of Medical Sciences, Shiraz, Iran; 2 Student Research Committee, School of Health and Nutrition, Shiraz University of Medical Sciences, Shiraz, Iran Correspondence: Mohammad Reza Fakoorziba, Ph.D. Research Center for Health Sciences, School of Health and Nutrition, P.O. Box: 71645-111, Shiraz University of Medical Sciences, Shiraz, Iran Tel: +98- 09177113112 Fax: +98-711-7250053 Email: fakoorziba@sums.ac.ir Received: 11 October 2012 Revised: 27 January 2013 Accepted: 8 April 2013 Original article Abstract Background: The German cockroach, Blattella germanica L. (Dictyoptera: Blattellidae), has become resistant to many insecticides due to control failures in hospital and student dormitory settings of southern Iran. Objective: This study was thus designed to detect and monitor carbamate resistance in two strains of German cockroach using lethal dose bioassay methods. Methods: Wild dormitory (D) and hospital (H) strains were collected. Adult males were subjected to the jar exposure procedure. A range of concentrations based on the world health organization (WHO) standard concentration of carbamate insecticides (carbaryl, bendiocarb, propoxur) were used. For each insecticide, four to seven different concentrations leading to >0% and <100% mortality were assayed. Ten insects were placed in each jar and the exposure time of contact was held constant for 30 minutes. Mortality data (as LD 50 ) were assessed using probit analysis. Results: Although both strains showed lethality values above those of the WHO standards, the H strain was more resistant to all of the three carbamate insecticides than the D strain, possibly due to the frequent and excessive dosage of these chemicals used in the hospital environment. The order of resistance for H strain was carbaryl > propoxur > bendiocarb. The ratio of LD 50 in H strain to that of D strain for bendiocarb was about twice that of the other two insecticides indicating that German cockroaches were most susceptible to bendiocarb under both environments. Conclusion: It is concluded that excessive reliance on carbaryl in both D and H settings has led to resistance. Please cite this article as: Moemenbellah-Fard MD, Fakoorziba MR, Azizi K, Mohebbi-Nodezh M. Carbamate Insecticides Resistance Monitoring of Adult Male German Cockroaches, Blattella germanica (L.), in Southern Iran. J Health Sci Surveillance Sys. 2013;1(1):41-47. Keywords: Blattella germanica; Carbamate; Insecticide; Cockroach; Resistance