Diuretic and Antidiuretic Hormones in the Blood-gorging Bug Rhodnius prolixus

Insect salt and water homeostasis is controlled by diuretic and antidiuretic hormones that can act upon the Malpighian tubules, midgut, and hindgut. Much is known about the physiological events stimulating diuresis and their signaling cascades; however, the factors inhibiting diuresis are less well known. An endogenous peptide in Rhodnius prolixus inhibits absorption by the anterior midgut and secretion from the Malpighian tubules. We have cloned the gene, sequenced this antidiuretic peptide, and examined gene expression via in situ hybridization. The antidiuretic peptide targets multiple tissues, and its discovery could facilitate the development of effective pest control agents to impede the transmission of Trypanosoma cruzi, the causative agent of Chagas' disease.