With the support of the local mosquito control agency, Navy scientists are using a hand-held fogger at the Stock Island fishing docks to test a method of controlling mosquitos that spread disease.

If successful, the technique could be used to protect warfighters detached to subtropical and tropical areas worldwide.

The project's overall purpose is to determine if the fogging method is efficient and effective in controlling the larvae of disease-carrying insects.

This particular experiment is targeting the Aedes aegypti mosquito, which is a carrier of dengue fever.
Scientists from the Navy Entomology Center of Excellence in Jacksonville, Florida, chose Key West as its testing site because of an outbreak of dengue fever in 2009; it was the first report of locally acquired cases in 50 years.

Local dengue transmission reoccurred in 2010 and cases are now being reported in Palm Beach, Martin, Hillsborough, Osceola and Seminole counties.

If the experiment proves to be successful, the military could use the hand-held thermal fogger to disperse larvicides in difficult terrain in tropical climates.

The new method would also lower the risks associated with applying pesticides.

The Aedes aegypti seeks clean, fresh water - like rain water - to lay its eggs, preferably in tiny, hard-to-reach sites. The Stock Island fishing docks have a plethora of hidden water pockets; a teaspoon of water is enough for breeding.

"It (the fogging technique) is great for broad areas but still concentrated enough that we don't need aerial application," said Catherine Pruszynski, research biologist with Florida Keys Mosquito Control District, which is collaborating with NECE. "It gets into the small cracks and crevices where inspectors can't reach," she added.

The fogging technology itself isn't new, noted NECE Medical Entomologist James Cilek, who is leading the experiment.

Foggers were used to spread pesticides in the 1940s, but the fog was petroleum-based and required a lot of fuel, which made it too expensive to use, he said. The process was revived in the 1970s but the fog was still petroleum-based, although it did use far less fuel.

The thermal fogger is primarily used for adult mosquitos, "we're seeing if we can use that same technology for larviciding," Cilek said.

The NECE experiment uses water-based larvicides, creating a fine mist that is safe to people, animals and other insects.

The testing, which was in its third local trial this week, involves three separate days of testing. The first establishes a control and the second and third test the effectiveness of two different larvicides, according to NECE Assistant Department Head Lt. Akiyo Arimoto.

Collection cups are placed in cryptic areas around the docks and collected after the fogging and then taken to the FKMCD lab. A set number of larvae are added, along with water, to the cups. The cups are checked 24 hours later and the number of surviving larvae is counted.

"So far, it's proved to be promising," Cilek said. "We are getting completing control of the larvae."
For future detachments in tropical areas, the hand-held fogger and water-based larvicides could lead to a win on the war with disease-carrying insects.

For more news from Naval Air Station Key West, visit www.navy.mil/.