b a ckground: the german cockroach, b lattella germanica is a major hygienic pest and mechanical vector for path- ogenic 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...

Animals balance their intake of specific nutrients, but little is known about how they do so when foraging in an environment with toxic resources and whether toxic foods promote adaptations that affect life history traits. In German cockroach (Blattella germanica) populations, glucose aversion has evolved in response to glucose-containing insecticidal baits. We restricted newly eclosed glucose-...

The effect of topically applied chlorpyrifos on acetylcholinesterase and other esterases in heads and decapitated bodies of CSMA and Crawford German cockroaches was examined with spectrophotometric enzyme assay and native polyacrylamide gel electrophoresis. The toxicity of chlorpyrifos was greatly reduced in decapitated CSMA male cockroaches with LD50 value 17.1-fold higher than that of normal ...

Fipronil, a phenylpyrazole insecticide, was made available in 1999 in bait formulations for use against the German cockroach, Blattella germanica (L.). We have investigated resistance to fipronil in the descendants of cockroaches collected just before, or contemporaneously with, the introduction of fipronil baits. Cockroaches were obtained in two types of settings: homes that either had or had ...

BACKGROUND AND OBJECTIVES Resistance amongst cockroaches has been reported to most of the spray insecticides. Imidacloprid gel baits, which can be selectively applied at the infested and potential harborages sites have been found effective in control of cockroach infestation in some laboratory studies but very few field studies are available. This study was therefore undertaken to evaluate the ...

W hich urban pest is the most difficult to control? Most PMPs say ants. But the answer to this question has shifted completely over the past 20 years — from cockroaches to ants. Today, few people consider the German cockroach a difficult pest to manage. What made the change is the invention of highly effective baits, in particular, gel baits. Then, the question is, why is the German cockroach s...

Eight essential oils of Chinese medicinal herbs (Angelica sinensis, Curuma aeruginosa, Cyperus rotundus, Eucalyptus robusta, Illicium verum, Lindera aggregate, Ocimum basilicum, and Zanthoxylum bungeanum) were obtained by hydrodistillation and the essential oil of Eucalyptus robusta leaves was analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 22 components of the essential oi...

An experimental 2.15% imidacloprid gel bait containing approximately 44% water was evaluated in laboratory and field studies against the German cockroach, Blattella germanica (L). In continuous exposure tests, toxicity and presumably bait consumption varied with cockroach stage, deprivation of competitive food, and temperature. The LT50 values for cockroaches provided with competitive food rang...

Boric acid dust has a long history as an insecticide in urban pest management, and it has been shown to be an effective alternative to conventional neurotoxic insecticides. However, dust formulations require specialized equipment and are difficult to apply, whereas gel and paste formulations contain large amounts of boric acid and tend to be less efficacious than other insecticide baits. The pu...