NRESISTANCE LEVEL OF THREE STRAINS OF GERMAN COCKROACHES, Blattella germanica FROM SEMARANG CITY TO FIPRONIL

Abstract

German cockroaches (Blattella germanica) are one of the common household pest insects frequently encountered in urban environments, including the city of Semarang. It has been reported that German cockroaches have developed resistance to 42 active insecticide ingredients, including fipronil. The aim of this study is to evaluate the toxicity level of 0.05% fipronil against German cockroaches from Semarang city  and determine their susceptibility to fipronil. Three strains of German cockroaches from Semarang, as well as one World Health Organization (WHO) standard strain from  Vector Control Research Unit (VCRU)  Universiti Sains Malaysia, were utilized for this experiment. The German cockroaches were tested using the baiting method. The research results indicate that 50% mortality of the field cockroach population occurred within the range of 9-27 hours after the application. Resistance ratio calculations showed that the resistance level of the three strains ranged from 2.55 to 7.57 times higher compared to the VCRU strain. This suggests that the three strains of German cockroaches from Semarang exhibit low-level resistance to 0.05% fipronil.