J. Econ. Entomo!. 90(5): 1073-1079 (1997) ABSTRACT A novel experimental design that selectively excluded feeding of adults or nymphs on insecticidal baits was used to distinguish mortality caused by ingestion of bait from mortality caused by horizontal transfer of insecticide by foraging to non foraging cockroaches. In large cage laboratory assays and in apartments, exposure of Blattella german...

Endotoxins are common indoor biocontaminants. Their levels have been shown to link to many sources and factors. One of them is cockroach infestation but the role of cockroaches and contamination mechanisms are unclear. We hypothesized that not only is cockroach infestation a sign of poor hygiene, but it also contributes to indoor endotoxins via fecal contamination. In this study, different cock...

Juvenile hormone (JH) exerts major pleiotropic effects on cockroach development and reproduction. The production of JH by the corpora allata (CA) in the adult female German cockroach, Blattella germanica, is dependent upon and modulated by both internal and environmental stimuli. Mating, intake of highquality food, social interactions, and the presence of vitellogenic ovaries facilitate JH synt...

Agel bait-resistantGerman cockroach,Blattella germanica (L.), strainCincywas collected in Cincinnati, OH. This strain exhibited a high level of behavioral resistance to Avert (0.05% abamectin) and Maxforce FC (0.01% Þpronil) gel baits. Topical application assays indicated moderate levels of physiological resistance of the Cincy strain to abamectin and Þpronil. Resistance ratios (based on LD50 v...

We aimed to elucidate why cockroaches do not produce vitellogenin in immature stages, by studying the appearance of vitellogenin mRNA in larvae of Blattella germanica. Treatment of female larvae in any of the last three instars with 1 microg of juvenile hormone (JH) III induces vitellogenin gene transcription, which indicates that the fat body is competent to transcribe vitellogenin at least fr...

The essential oil of catnip, Nepeta cataria L., contains two isomers of nepetalactone, E,Z-and Z,E-nepetalactone, and was tested for repellent activity to adult male German cockroaches, Blattella germanica (L.), in a choice-test arena. The two isomers of nepetalactone were purified by using preparative thin-layer chromatography and tested for behavioral activity in the choice-test arena. Signif...

Blattella germanica (L.) (Dictyoptera: Blattellidae) that were fed fipronil bait produced liquid excretions that were toxic to conspecifics. We have used a combination of analytical and behavioral assays to localize the source, to elucidate the time course, and to evaluate the role of these excretions in facilitation of secondary kill. Fipronil excretion coincided with the onset of the paralyti...

Imidacloprid a neonicotinoid insecticide was administrated by injection to newly emerged adults of the German cockroach Blattella germanica (Insecta, Dictyoptera) at 0.0002% and 0.0005% doses corresponding to the LD50 and LD90 respectively. The insecticidal effect of compound was investigated on ovarian growth during the first gonadotrophic cycle (0, 2, 4 and 6 days) under laboratory conditions...