The presence of Gram-negative bacteria in cuticle and alimentary tract of cockroaches collected from four selected areas of Dhaka city was investigated. Using detection key, a total of 12 cockroaches were identified as Periplaneta americana (58.33%), Blattella germanica (33.33%) and Blatta orientalis (8.33%). From these three species 54 different bacterial isolates were obtained. Out of them, 3...

In many animal species, social interactions can influence the morphology, physiology and behavior of individuals, including their rate of development and reproduction. Reproduction in cockroaches is regulated by juvenile hormone III (JH), and social interactions have been shown to accelerate female reproduction in the German cockroach, Blattella germanica (L.), by stimulating JH production. How...

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)...