Patterns of juvenile hormone have been intensively studied in the cockroach Blattella germanica under different physiological situations. However, data have been mainly obtained in vitro, and refer to hormone synthesized by isolated corpora allata, whereas information available on hormone concentration in the hemolymph is restricted to adult females. In order to complement our studies in vitro,...

In 2009 we reported that depletion of Dicer-1, the enzyme that catalyzes the final step of miRNA biosynthesis, prevents metamorphosis in Blattella germanica. However, the precise regulatory roles of miRNAs in the process have remained elusive. In the present work, we have observed that Dicer-1 depletion results in an increase of mRNA levels of Krüppel homolog 1 (Kr-h1), a juvenile hormone-depen...

The fumigant toxicity of various essential oils and selected monoterpenoid components were tested against the adult German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae). Responses varied according to plant material, concentration, and exposure time. High insecticidal activity against adult B. germanica specimens was achieved with allyl isothiocyanate (component of horseradish)...

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...

In some ants, bees, and wasps, workers kill or ‘‘police’’ male eggs laid by other workers in order to maintain the reproductive primacy of the queen. Kin selection theory predicts that multiple mating by the queen is one factor that can selectively favor worker policing. This is because when the queen is mated to multiple males, workers are more closely related to the queen’s sons than to the s...

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...

BACKGROUND Studies in patients with allergic rhinitis living in the Free State have showed grass pollens to be the predominant allergens, with house-dust mite sensitisation being less prevalent than in the coastal areas and a low rate of sensitisation to the storage mite Lepidoglyphus destructor. No studies have been conducted on sensitisation to the other storage mites, spider mites or cockroa...