Dr. Patricia Pietrantonio, associate professor of entomology with the Texas Agricultural Experiment Station, is leading a team of researchers studying the hormone-controlled mechanism by which mosquitoes excrete waste.

"This research has far-reaching implications for the discovery of new alternatives for insect control," Pietrantonio said.

Presently, a human vaccine for yellow fever exists, but none for dengue.

The researchers are hoping the studies will reveal how the female mosquito's system produces a diuretic response during and after a blood meal. Aedes aegypti feed during the daytime and need a blood meal to reproduce. The blood meal triggers vitellogenesis (formation of the yolk of an egg) and oogenesis (egg formation).

"They feed on humans and animals, and if the blood meal is successful, then reproduction begins," Pietrantonio said. "They can lay eggs for one to two days, and then they can feed again. The reproductive potential of the female is quite significant."

As mosquitoes feed, they begin excreting a clear liquid very quickly.

"Diuresis, or the production of urine, is very fast. If they are still engorged, they fly very poorly and susceptible to being slapped by a human or eaten by a predator," she explained.

"We want to know how the mosquito gets rid of all this water so fast. It is very complex process."

To do so, researchers are cloning mosquito genes and studying cell receptors, the proteins in the cell membranes involved in the transfer of information from one area of the cell to another. The process is regulated by hormones.

Hormones are released
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Contact: Dr. Patricia Pietrantonio
p-pietrantonio@tamu.edu
979-845-9728
Texas A&M University - Agricultural Communications
24-Mar-2004