BACKGROUND The German cockroach, Blattella germanica is a major hygienic pest and mechanical vector for pathogenic agents in hospitals and residential areas. The development of insecticide resistance is a serious problem in controlling of this pest. Toxicity of four commonly used insecticides (permethrin, cypermethrin, malathion and chlorpyrifos) against two hospital- collected strains of the G...

OBJECTIVE To evaluate the insecticidal effect of diatomaceous earth (DE) against adults and nymphs of Blattella germanica. METHODS This cross sectional study has been done on the laboratory strain of German cockroaches. Two stages, nymph and adult, were exposed to six dose rates of the DE, 2.5, 5, 10, 15, 20 and 25 g/m(2), at 24, 48 and 72 h exposure period. Mortality (number of dead cockroac...

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) an...

Numerous studies have shown that German cockroaches, Blattella germanica (L.), are often resistant to insecticides in settings where insecticides have been used extensively in the past. We have now examined resistance in German cockroaches collected in homes in which insecticide usage has been minimal, and resident-initiated at best. Resistance to propoxur, chlorpyrifos, pyrethrins, permethrin,...

Aggregation of the German cockroach, Blattella germanica, is regulated by fecal aggregation agents (pheromones), including volatile carboxylic acids (VCAs). We demonstrate that the gut microbial community contributes to production of these semiochemicals. Chemical analysis of the fecal extract of B. germanica revealed 40 VCAs. Feces from axenic cockroaches (no microorganisms in the alimentary t...

The cytochrome P450 monooxygenases are an important metabolic system whose level of activity can be influenced by several dietary constituents. We examined the effects of six known P450 inducers on the levels of total cytochromes P450, cytochrome b(5), and six monooxygenase activities in adult German cockroaches. In addition, the levels of CYP6L1 and CYP9E2 mRNA were also investigated. Phenobar...