Wolbachia mosquitoes released in Lower Keys

Mosquitoes are delivered in cardboard tubes, each one containing 1,000 male Aedes aegypti bugs.
Mosquitoes are delivered in cardboard tubes, each one containing 1,000 male Aedes aegypti bugs. Mosquito Control District

A cooler containing 20 cardboard tubes arrived at the Florida Keys Mosquito Control District building on Stock Island Tuesday, shipped overnight from Kentucky.

In each tube were 1,000 mosquitoes infected with the natural bacteria Wolbachia. The delivery was the first of many as 40,000 bugs, all male, will be released each week for the next 12 weeks in a 10-acre area on Stock Island.

“A thousand are released at 20 release points on Tuesdays and Fridays,” said Beth Ranson, public information officer for the Mosquito Control District, following the first release Tuesday afternoon. “You open the tube and they swarm around for about a minute. After a while you can’t even tell they’re there.”

The trial is being carried out to drive down the local population of Aedes aegypti mosquitoes, which carry Zika and other viruses. The mosquitoes are reared by biotech company MosquitoMate, which received approval from the U.S. Environmental Protection Agency in October to use Wolbachia in the Florida Keys trial.

The release points are in an area south of Grunt Street to Peninsular Avenue, where the mosquitoes will seek out wild female mosquitoes with which to mate. The eggs will never hatch due to the Wolbachia, which is found in 50 percent of insects and is not harmful to humans, according to Dr. Stephen Dobson, founder and chief executive of MosquitoMate.

“We reared those mosquitoes last week,” Dobson said of the bugs released Tuesday. “There are good historical records of high numbers of Aedes aegypti in that trial area.”

Dobson said for the Wolbachia method to work and start driving down the number of mosquitoes, there needs to be a ratio of seven male Wolbachia-infected mosquitoes to every one naturally found in the trial site.

“We’ve never released in Florida, so we’re hoping to learn through this process,” he said.

Katie Atkins: 305-440-3219