Officials also are considering locations for a separate test of Aedes aegypti mosquitoes genetically modified to produce offspring that die outside a lab.

The corridors of the lab were lined with newspaper pictures of the black-and-white striped mosquito Aedes aegypti, the predominant carrier of Zika.

Zika is transmitted to people primarily through the bite of an infected Aedes aegypti species mosquito, but it can also be spread during sex.