We have found that whether a female German cockroach, Blattella germanica (L.), is kept alone or in the presence of another female has a major impact on how fast it reproduces and how much it eats. By the sixth day of adulthood, females paired since adult eclosion had substantially larger oöcytes than did females isolated during the same time, and females paired with intact females, or with one...

Insect cells of an established line, Drosophila Kc cells, take up and metabolize juvenile hormone (JH). The cytoplasm of these cells contains a protein that binds JH with specificity, saturability, and high affinity (K(d) = 1.56 x 10(-8) M). The kinetics for the specific binding and dissociation of JH I were independently measured, and the rate constants were found to be k(a) = 1.3 x 10(6) M(-1...

Juvenile hormone esterase (JHE) is a carboxylesterase that has attracted great interest because of its critical role in regulating larval to adult transition in insects and other arthropods. Previously, we characterized an ecdysteroid sensitive and juvenile hormone non-susceptible juvenile hormone esterase related gene (SnJHER) in the corn stalk borer, Sesamia nonagrioides. SnJHER was rhythmica...

Epidermis, Tenebrio molitor L., target organ function, juvenile hormone receptor In v ivo tests give evidence that the epidermis is the target organ for the juvenile hormone of insects. A study of the distribution of injected 10,ll-epoxy-6,7-trans-2,3-trans-farnesylpropenylether and of its metabolic products in epidermis, lymphae, and other organs demon­ strated that the unaltered ether accumul...

Nereidae are vital to the functioning of estuarine ecosystems and are major components in the diets of over-wintering birds and commercial fish. They use environmental cues to synchronize reproduction. Photoperiod is the proximate cue, initiating vitellogenesis in a temperature-compensated process. The prevailing paradigm in Nereidae is of a single 'juvenile' hormone controlling growth and repr...

Pupal diapause in the cecropia silkmoth is terminated by activation of the prothoracic glands. Implantation of adult male cecropia corpora allata or injection of juvenile hormone-I (JH-I) or juvenile hormone-I acid (JH-I acid) causes initiation of development in debrained, allatectomized diapausing pupae. The subsequent development results in formation of second pupae or pupal-adult intermediat...

Juvenile hormone III biosynthesis in vitro by the corpora allata of adult female Bluttellu germanica is precisely correlated with the gonotrophic cycle. Farnesoic acid-stimulated rates of juvenile hormone synthesis are always higher than the corresponding basal rates, and follow the same pattern of cyclic changes during oijcyte maturation. Both basal and farnesoic acid-stimulated rates decline ...

Five neuropeptides with known allatotropic or allatostatic activity in other insect species were examined for their effects on honey bee corpora allata. Using an in vitro radiochemical assay, we assessed the ability of these peptides to affect the biosynthesis of juvenile hormone III and its immediate precursor methyl farnesoate, as well as their effects on the conversion of methyl farnesoate i...