Small Island, Big Experiment

The first thing Billy Ryan does after he arrives at work most mornings is drive to a yacht club or construction company lot, crawl into a mangrove, and stand for 60 seconds to count the mosquitoes that land on him. If there are five or more, he’ll request that a crew come spray the area the next day. From there, the 56-year-old inspector with the Florida Keys Mosquito Control District will visit commercial and residential properties, hunting for standing water and the mosquito larvae and pupae that are frequently found within it. “With salt marsh mosquitoes, you can kill 95 percent on a good night,” said Michael Doyle, who was director of the district from 2011 until he resigned on Sept. 1. “With Aedes aegypti, you’re lucky if it’s 50 percent.”  This is why Doyle and his colleagues have been searching for new tools to beat back the Aedes aegypti on the islands — and why they’re now involved in a messy public battle over genetically modified organisms. The mosquito control district has been in talks for years with Oxitec, a British company that engineered a strain of mosquitoes with a gene that causes the insect’s offspring to die before reaching maturity, and in August, the company finally made its way through the maze of the federal government’s approval process for field testing.