Many insects respond to a bacterial infection with the stimulation of distinct cellular and humoral defense system, that cooperate in a more or less integrated way to decrease the chance of microorganisms becoming pathogens. Cellular reactions include phagocytosis, nodule formation, and in some cases encapsulation and other factors related to immune system as prophenoloxidase (proPO) system, le...

We have characterized sulfated glycosaminoglycans from ovaries of the blood-sucking insect Rhodnius prolixus, and determined parameters of their synthesis and distribution within this organ by biochemical and histochemical procedures. The major sulfated glycosaminoglycan is heparan sulfate while chondroitin 4-sulfate is a minor component. These glycosaminoglycans are concentrated in the ovarian...

Rhodnius prolixus, the principal Chagas disease vector, requires a blood meal to complete its moult cycle into the next stage. Allatotropins (ATs), a family of peptides first isolated from Manduca sexta, have been shown to regulate the biosynthesis of juvenile hormone, an insect growth and development hormone; however, ATs, being multimodal peptides, also exhibit myotropic effects on some insec...

Rhodnius prolixus periodically gorges on a blood meal that could compromise salt and water balance. This, however, is prevented by rapid production of urine within minutes of feeding. The Malpighian tubules increase their rate of secretion 1,000 fold leading to the production of a hypo-osmotic urine that is high in NaCl content. Feeding and post-prandial diuresis in R. prolixus are tightly coor...

Blood-sucking insects experience thermal stress at each feeding event on endothermic vertebrates. We used thermography to examine how kissing-bugs Rhodnius prolixus actively protect themselves from overheating. During feeding, these bugs sequester and dissipate the excess heat in their heads while maintaining an abdominal temperature close to ambient. We employed a functional-morphological appr...

This study attempted to quantify the transmission of Trypanosoma cruzi in children less than 15 years of age in Barinas State, Venezuela and investigate risk factors for infection. Among 3,296 children, 4 (0.12%) were seropositive. The mother of one child also was also seropositive, which suggested that congenital transmission is a possible risk factor for Chagas disease in this area. Seropreva...

Plant sucking heteropteran bugs feed regularly on small amounts of K(+)-rich plant material, in contrast to their hematophagous relatives which imbibe large volumes of Na(+)-rich blood. It was anticipated that this would be reflected in the endocrine control of Malpighian tubule (MT) secretion. To explore this, neuroendocrine factors known to influence MT secretion were tested on MT of the pent...

Rhodnius prolixus, the vector of human Chagas disease, is a hemipteran insect that undergoes rapid post-feeding diuresis following ingestion of a blood meal that can be up to 10 times its initial body weight. Corticotropin-releasing factor-related diuretic hormone (Rhopr-CRF/DH) and serotonin are neurohormones that are synergistic in increasing rates of fluid secretion by Malpighian tubules dur...

The pioneering work of Simon Maddrell established that the rapid postprandial diuresis of the haematophagous insect Rhodnius prolixus is controlled by a diuretic hormone and demonstrated the role of the Malpighian tubules in meeting the volumic, osmotic and ionic challenges posed by an enormous blood meal. A number of diuretic and antidiuretic hormones that control secretion of primary urine by...