Wolbachia...

Three times a week, on a quiet block of Stock Island on the Florida Keys, 25,000 of the world's deadliest creatures are released into the wild.
Not to fear. While these are mosquitoes,  the creature responsible for more human deaths each year than any other on the planet, they're all males. It's only the females that bite.

The Aedes aegypti mosquito is responsible for spreading dengue fever, chikungunya, yellow fever, and, most recently, Zika. It's not the deadliest of all the mosquitoes, that title goes to the species that carry malaria, but it's causing the most grief here in the United States.

These experimental bugs carry a secret weapon: they're infected with a bacteria called wolbachia that interferes with reproduction, essentially aiming to spread infertility through Aedes aegypti in the area.
It's a symbiotic bacteria in insects."

So when these males infected with wolbachia are released into the wild, they mate with uninfected females, and the resulting eggs don't hatch. Simple...