Has an oostatic activity. Inhibits trypsin biosynthesis in the midgut epithelial cells which indirectly reduces the vitellogenin concentration in the hemolymph resulting in inhibition of oocyte development. Secreted from the ovary, starting 18 hours after a blood meal, circulates in the hemolymph. Expressed in the anterior region of the follicle cells. Synthesized and released from follicular epithelium 18-24 hours after a blood meal. Synthesis peaks at 36 hours and stops at 56 hours. Can potentially be used as a larvicide. The stable three-dimensional conformation of the decapeptide means it is not degraded by gut proteolytic enzymes and can traverse the gut epithelial cells into the hemolymph of adults and larvae. Hormone fed to different species of mosquito larvae stops food digestion and causes larval mortality. The tetrapeptide (DYPA) is as effective as the decapeptide. Belongs to the vitelline membrane protein family.