The literature suggests that several species of insects can convert Czs and Czs sterols to cholestane derivatives. According to Bergmann (l), cholesterol is the major sterol constituent (85%) and the plant sterol sitosterol a minor component of chrysalis oil obtained from the silkworm Bombyx mori, although this insect feeds exclusively on mulberry leaves. More recently, Bergmann and Levinson (2...

An insect oocyte with a disc-shaped sink of current on its ventral surface during a vitellogenic phase of development is used to demonstrate modeling of expected currents arising from a mathematically defined source. A simple model with an analytical solution for the expected currents is compared to a more complex model in which expectations are computed by mathematical integration. The current...

Recent studies in vitro have reported that the Methoprene-tolerant (Met) and Taiman (Tai) complex is the functional receptor of juvenile hormone (JH). Experiments in vivo of Met depletion have confirmed this factor's role in JH signal transduction, however, there is no equivalent data regarding Tai because its depletion in larval or nymphal stages of the beetle Tribolium castaneum and the bug P...

A new DNA virus (Parvoviridae: Densovirinae, Densovirus) was isolated and purified from descendants of field-collected German cockroaches, Blattella germanica. Viral DNA and cockroach tissues infected with B. germanica densovirus (BgDNV) were examined by electron microscopy. Virus particles, about 20 nm in diameter, were observed both in the nucleus and in the cytoplasm of infected cells. Virus...

BACKGROUND Cockroaches are among the medically important pests found within the human habitations that cause serious public health problems. They may harbor a number of pathogenic bacteria on the external surface with antibiotic resistance. Hence, they are regarded as major microbial vectors. This study investigates the prevalence and antibiotic resistance of Gram-negative pathogenic bacteria s...