( Discovery has implications for control ...)University of Nevada, Reno research team discovers hormone that causes malaria mosquito to urinate

Prior to coming to Nevada 16 years ago, David Schooley was a key figure at a small company in Palo Alto, Calif. that developed methoprene, an insecticide that halts the maturation of insect larvae to adults.

Methoprene, which has the same effect as an insect hormone called juvenile hormone, also stops the insect from reproducing. It is being used heavily throughout the United States to help prevent the spread of West Nile Virus.

Schooley's contribution to the development of methoprene was to prove that it is harmless to animals and the environment.

"Table salt is far more toxic," said Schooley, a professor of biochemistry at the University of Nevada, Reno's College of Agriculture, Biotechnology and Natural Resources

The problem with methoprene, however, is that for a species such as the tobacco hornworm, methoprene causes it to grow larger instead of transforming into a moth, enhancing the pest's ability to devastate crops.

"It's not a great way to sell an insecticide to a farmer," Schooley said. "Most money in pesticide development is in making insecticides for pests which attack crops."

This is what lead Schooley, and his colleague Geoff Coast of the University of London, down the path of finding a way to control insects that are pests at the larval stage, a path that has them instead potentially paving the way for better mosquito control.

A potential solution to the problem of killing insects at any stage of development may be found in peptide hormones, small proteins in all animals that regulate most bodily functions. While researching the genome of the malaria mosquito, Schooley discovered two different types of diuretic hormones similar to those from other insect species. These were synthesized at the University of Nevada, Reno then sent to London to study their effects on mosquitoes.

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Source:University of Nevada College of Agriculture, Biotechnology, and Natural Resources