United States | News & Politics

Fertility alone may not even be a factor. For example, one thing that could've easily happened is that they significantly increased overall mosquito population, and the infertile mosquitoes could've been more appealing food for predators than smaller newly hatched mosquitoes. The number of fertile males may not even be a limiting factor because each female lays many eggs. As I said earlier, biological systems are complex and it's very easy to end up with unintended consequences that are impossible to predict before hand.